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Pediatrics_Nelson. Pityriasis rosea is a benign, self-limited eruption that may occur at any age, with peak incidence during adolescence. A solitary, 2to 5-cm, pink, oval patch with central clearing, theso-called herald patch, is the first manifestation of the eruption.The herald patch typically is found on the breast, lower torso, orproximal thigh and is often misdiagnosed as fungal or eczematous in origin. One to 2 weeks later, a generalized eruptionoccurs on the torso and proximal extremities. Multiple 0.5to2-cm, oval to oblong, red or tan macules with a fine, branlikescale are characteristically arranged parallel to skin tensionlines (Christmas tree pattern). Rarely, the eruption may have aninverse distribution involving the axillae and groin or a papularor papulovesicular appearance. Mild prodromal symptoms maybe present with the appearance of the herald patch, and pruritusis present in 25% of cases. The eruption lasts 4 to 14 weeks, withgradual resolution. Residual hyperpigmentation or


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Pediatrics_Nelson. symptoms maybe present with the appearance of the herald patch, and pruritusis present in 25% of cases. The eruption lasts 4 to 14 weeks, withgradual resolution. Residual hyperpigmentation or hypopigmentation can take additional months to clear. Treatment is unnecessary, though pruritus can be managed with oral antihistamines, phototherapy, and low-potency topical corticosteroids.


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Pediatrics_Nelson. Psoriasis is a common papulosquamous condition characterized by well-demarcated, erythematous, scaling papules andplaques. Psoriasis occurs at all ages, including infancy, withonset of 30% of cases during childhood. The disease is characterized by a chronic and relapsing course, although spontaneous remissions can occur. Infections (especially Streptococcus pyogenes), stress, trauma, and medications may cause diseaseexacerbations. Various subtypes of psoriasis exist. The mostcommon variety is plaque-type psoriasis (psoriasis vulgaris), which can be localized or generalized. The lesions consist ofround, well-demarcated, red plaques measuring 1 to 7 cm withmicaceous scale, which is distinctive in its thick, silvery appearance with pinpoint bleeding points revealed on removal of thescales (Auspitz sign). The lesions of psoriasis have a distinctivedistribution involving the extensor aspect of the elbows andknees, posterior occipital scalp, periumbilical region, lumbosacral region, and


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Pediatrics_Nelson. (Auspitz sign). The lesions of psoriasis have a distinctivedistribution involving the extensor aspect of the elbows andknees, posterior occipital scalp, periumbilical region, lumbosacral region, and intergluteal cleft. Children often have faciallesions involving the superomedial aspect of the eyelids. Nailplate involvement is common and includes pitting, onycholysis, subungual hyperkeratosis, and oil staining (reddish brownsubungual macular discoloration). Guttate (numerous smallplaques diffusely distributed on the torso), erythrodermic (covering large body surface areas), inverse (moist red patches affecting body folds), and pustular forms may occur.


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Pediatrics_Nelson. The foundation of therapy is topical corticosteroids. Treatment of psoriasis with oral corticosteroids can induce pustularpsoriasis and should be avoided. Because of the risk of atrophy,striae, and telangiectases, especially when potent fluorinated corticosteroid preparations are administered long-term, thegoal is to use the least potent corticosteroid necessary. Topical vitamin D analogs, salicylic acid, and tar preparations areuseful adjuvants to topical corticosteroids. Phototherapy withultraviolet B (UVB) light can be useful as secondary therapy inolder children. Extensive plaque or guttate, erythrodermic, andpustular psoriasis may necessitate systemic treatments withimmune suppressive medication (methotrexate, cyclosporine,tumor necrosis factor-α antagonists). Disease triggers such asinfection or medications should be identified and removed.


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Pediatrics_Nelson. Birthmark is a term that describes congenital anomalies of the skin. It should not be used as a definitive diagnosis because congenital skin lesions vary greatly in their appearance and prognosis. The differential diagnosis of various birthmarks is listed in Table 193-1.


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Pediatrics_Nelson. The most frequently encountered pigmented lesion is dermal melanosis, which occurs in 70% to 90% of African-American, Hispanic, Asian, and Native American infants and in approximately 5% of white infants. This is a congenital lesion caused by entrapment of melanocytes in the dermis during their migration from the neural crest into the epidermis. Although most of these lesions are found in the lumbosacral area (Mongolian spot), they also occur at other sites such as the buttocks, flank, extremities, or, rarely, the face (Fig. 193-1). Single or multiple, poorly demarcated, gray-blue patches up to 10 cm in size may be present. Most lesions gradually disappear during the first few years of life; aberrant lesions in unusual sites are more likely to persist.


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Pediatrics_Nelson. Café au lait macules are pigmented macules or patches, whichmay be present in a newborn but tend to develop during childhood (Fig. 193-2). They range in color from very light brownto a chocolate brown. Up to five café au lait macules are foundin 1.8% of newborns and 25% to 40% of normal children, and have no significance. Children with six or more café au laitmacules (0.5 cm in diameter before puberty or greater than 1.5 cm in diameter after puberty), especially when accompaniedby axillary or inguinal freckling, should be evaluated carefully Brown (<20 cm)/plaque Congenital melanocytic nevus Variable Low risk of melanoma Brown (>20 cm)/plaque Giant congenital melanocytic Trunk most common Risk of melanoma and nevus Brown-“flesh-colored”/plaque Epidermal nevus Variable, trunk and neck May enlarge with time Red/patch Port-wine stain (nevus flammeus) Variable, face most common May be associated with Sturge-Weber syndrome


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Pediatrics_Nelson. Red/patch Port-wine stain (nevus flammeus) Variable, face most common May be associated with Sturge-Weber syndrome Red/patch Salmon patch (nevus simplex) Glabella, eyelids, nape of neck Improves or resolves with time Red/papule or plaque Hemangioma Variable May be associated with liver hemangiomas, airway hemangiomas, and PHACE syndrome Blue-purple/nodule Cephalohematoma Scalp Resolves with time Blue-purple/plaque Venous, lymphatic, or mixed Variable Intermittent swelling and pain malformation Hypertrichosis/tumor Plexiform neurofibroma Trunk most common Associated with neurofibromatosis type 1 for additional stigmata of neurofibromatosis type 1. Other disorders also associated with café au lait macules include the other forms of neurofibromatosis, Legius syndrome, tuberous sclerosis, McCune-Albright syndrome, multiple lentigines/LEOPARDsyndrome, Noonan syndrome, and Russell-Silver syndrome. Figure 193-1 Dermal hypermelanosis (back). Figure 193-2 Cafe au lait spots (leg).


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Pediatrics_Nelson. Approximately 1% to 2% of newborns have congenital melanocytic nevi. Smaller lesions (as opposed to giant pigmented nevi) are brown patches or plaques, often with an oval or lancet configuration. Lesions may resemble café au lait macules initially, but darker pigmentation, variegated speckles, textural changes, and elevation develop with time and help to differentiate these lesions (Fig. 193-3). Thick, dark, coarse hair frequently is associated with congenital melanocytic nevi (Fig. 193-4). These lesions vary in site and size but are most often solitary. Congenital melanocytic nevi pose a very slightly increased risk for the development of malignant melanoma, usually developing during adulthood. Surgical removal may be considered to improve the cosmetic appearance of the patient or to reduce the likelihood of malignant transformation, although some patients and physicians elect for observation. Excisional biopsy is indicated when malignant change is suspected.


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Pediatrics_Nelson. Giant congenital melanocytic nevi are defined as nevi that would be approximately 20 cm in length in adulthood; in a neonate, this translates to 9 cm on the head and neck and 6 cm on the rest of the body. These lesions appear as color variegated, light brown to black patch or plaques, sometimes with smaller macules and papules (satellite nevi) in addition. The affected skin may be smooth, nodular, or leathery. Prominent, dark hypertrichosis is often present. Neuromelanosis, the presence of melanocytes in the central nervous system, may be associated with giant congenital melanocytic nevi. Affected patients may be asymptomatic or have hydrocephalus and seizures; in symptomatic patients, death often results during early childhood. Malignant melanoma develops in approximately 2% to 10% of patients with giant congenital melanocytic nevi, in either the cutaneous lesion or the neural melanocytes. In contrast to small and medium congenital melanocytic nevi, melanoma is more likely to develop


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Pediatrics_Nelson. with giant congenital melanocytic nevi, in either the cutaneous lesion or the neural melanocytes. In contrast to small and medium congenital melanocytic nevi, melanoma is more likely to develop during childhood. Because of the incidence of malignant degeneration and extensive deformity, surgical excision should be considered for resectable lesions. The use of tissue expansion techniques has greatly improved the capability for surgical removal of large lesions.


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Pediatrics_Nelson. Figure 193-3 Congenital melanocytic nevus (buttock). Figure 193-4 Hairy congenital nevus. Acquired melanocytic nevi are common skin lesions. Melanocytic nevi may occur at any age; however, the lesions developmost rapidly in prepubertal children and teenagers. Melanocytic nevi are well-delineated, round to oval, brown maculesand papules. Lesions are most common on the face, upper torso,and arms. Family history, fair skin, and sun exposure are considered major risk factors. Irregular pigmentation, rapid growth,bleeding, and a change in configuration or borders suggest signsof malignant degeneration and biopsy should be performed.Malignant melanoma is rare in childhood; however, there isan alarming increase in incidence in adolescence, especially inthose who use indoor tanning. Education of parents and children regarding the risks of sun exposure, appropriate sun protection, and recognition of worrisome lesions is important.


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Pediatrics_Nelson. Vascular anomalies can be divided into two major categories:tumors and malformations. Vascular tumors are characterized by hypercellularity, proliferation, and growth. Vascular malformations, however, are developmental defects derived from the capillary, venous, arterial, or lymphatic vessels. In contrast tohemangiomas, vascular malformations remain relatively staticover time. Differentiating between these entities is importantbecause they have different prognoses and clinical implications. Available @ StudentConsult.com


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Pediatrics_Nelson. Hemangiomas are the most common soft tissue tumors of infancy, occurring in approximately 5% to 10% of 1-year-old infants. In newborns, hemangiomas may originate as a pale white macule with threadlike telangiectasia. When the tumor proliferates, it assumes its most recognizable form as a bright red, lobulated plaque or nodule (superficial component, Fig. 194-1). Hemangiomas that lie deeper in the skin are soft, warm masses with a slightly bluish discoloration (deeper component). Frequently, hemangiomas have both a superficial and a deep component. They range from a few millimeters to several centimeters in diameter and are usually solitary; 20% involve multiple lesions. Hemangiomas occur predominantly in females (3:1) and have an increased incidence in premature infants. Approximately 55% are present at birth; the rest develop in the first weeks of life. Superficial hemangiomas reach their maximal size by 6 to 8 months, but deep hemangiomas may grow for 12 to 14 months. They then


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Pediatrics_Nelson. 55% are present at birth; the rest develop in the first weeks of life. Superficial hemangiomas reach their maximal size by 6 to 8 months, but deep hemangiomas may grow for 12 to 14 months. They then undergo slow, spontaneous resolution, which takes 3 to 10 years.


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Pediatrics_Nelson. Figure 194-1 Hemangioma (chest). Despite the benign nature of most cutaneous hemangiomas, there may be the risk of functional compromise or permanent disfigurement depending on the location and extent. Ulceration, the most frequent complication, can be painful and increases the risk of infection, hemorrhage, and scarring. Areas frequently associated with complications include the periocular region, lip, nasal tip, beard, face (large lesions), groin, and buttocks.


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Pediatrics_Nelson. Periorbital hemangiomas pose considerable risk tovision and should be monitored carefully. Amblyopia canresult from the hemangioma causing obstruction of the visual axis or pressure on the globe, resulting in astigmatism. If there is any concern, the patient should have urgentevaluation by an ophthalmologist. Treatment may be indicated to prevent blindness. Subglottic hemangiomas manifest as hoarseness and stridor; progression to respiratoryfailure may be rapid. Symptomatic airway hemangiomasdevelop in more than 50% of infants with extensive facialhemangiomas on the chin and jaw (beard distribution);any infant with a beard hemangioma should be referredfor laryngoscopy. Multiple cutaneous (diffuse hemangiomatosis) and large facial hemangiomas may be associated with visceral hemangiomas. Extensive cervicofacialhemangiomas may be associated with multiple anomalies,including posterior fossa malformations, hemangiomas,arterial anomalies of the cerebrovasculature, coarctation of aorta and


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Pediatrics_Nelson. cervicofacialhemangiomas may be associated with multiple anomalies,including posterior fossa malformations, hemangiomas,arterial anomalies of the cerebrovasculature, coarctation of aorta and cardiac defects, and eye abnormalities (PHACE syndrome). Lumbosacral hemangiomas suggest an occultspinal dysraphism with or without anorectal and urogenital anomalies. Magnetic resonance imaging of the spine is indicated in all patients with midline cutaneous hemangiomas in the lumbosacral area.


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Pediatrics_Nelson. Most hemangiomas do not necessitate medical intervention and involute spontaneously; however, if complicationsarise and treatment is warranted, oral propranolol is themainstay of therapy. A pyogenic granuloma is an acquired, benign vascular tumor commonly seen in children. Initially, the lesions appear as pink-red papules that often arise after minor trauma, growing rapidly over a period of weeks into a bright red, vascular, often pedunculated papule measuring 2 to 10 mm. The lesions often have the appearance of granulation tissue and are very friable. They may occur anywhere on the body, but the head, neck, and upper extremities are most commonly affected. When traumatized, these lesions may bleed profusely, often requiring emergent medical attention. Surgical excision is the most definitive treatment option, though pulsed dye laser can be useful for very small lesions.


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Pediatrics_Nelson. Port-wine stains (nevus flammeus, capillary malformation) aremalformations of the superficial capillaries of the skin. Theselesions are present at birth and should be considered permanent developmental defects. They do not enlarge after birth; any apparent increase in size is caused by growth of the child.A port-wine stain may be localized to any body surface, butfacial lesions are the most common. They are pink-red, sharplydemarcated macules and patches in infancy (Fig. 194-2). With time, they darken to a purple or port-wine color and maydevelop a pebbly or slightly thickened surface. Vascular blebsmay form within the lesions and become symptomatic or bleed.The most successful treatment modality in use is the pulsed dyelaser, which can result in 80% to 90% improvement in theselesions after a series of treatment sessions and can avoid future complications associated with vascular dilation. Treatment ismore effective if undertaken in infancy. Overgrowth of underlying bone can occur and


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Pediatrics_Nelson. a series of treatment sessions and can avoid future complications associated with vascular dilation. Treatment ismore effective if undertaken in infancy. Overgrowth of underlying bone can occur and is frequently seen with facial lesions.Affected patients often need maxillofacial intervention frommalalignment that develops.


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Pediatrics_Nelson. Most port-wine stains occur as isolated defects and do not indicate systemic malformations. Rarely, they may suggest ocular defects or specific neurocutaneous syndromes. Sturge-Weber syndrome (encephalotrigeminal angiomatosis) may occur with a facial port-wine stain, usually in the cutaneous distribution of the first branch of the trigeminal nerve. Other features include leptomeningeal angiomatosis, mental retardation, seizures, hemiparesis contralateral to the facial lesions, ipsilateral intracortical calcification, and frequent ocular manifestations such as buphthalmos, glaucoma, angioma of the choroid, hemianoptic defects, and optic atrophy. Anticonvulsant therapy and neurosurgical procedures have been of value in some patients. Glaucoma can occur in association with port-wine stains located on the eyelid, even in the absence of Sturge-Weber syndrome, and these patients need lifelong monitoring of ocular pressures. Klippel-Trénaunay-Webersyndrome is characterized by the triad of


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Pediatrics_Nelson. located on the eyelid, even in the absence of Sturge-Weber syndrome, and these patients need lifelong monitoring of ocular pressures. Klippel-Trénaunay-Webersyndrome is characterized by the triad of capillary and venous malformations, venous varicosities, and hyperplasia of the soft tissues—and often bone—of the involved area. The lower limb is most commonly affected. A port-wine stain overlying the spine may rarely be a marker of spinal dysraphism or an intraspinal vascular malformation.


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Pediatrics_Nelson. Figure 194-2 Port-wine stain (face). A salmon patch (nevus simplex, stork bite, angel’s kiss) is avariant of nevus flammeus that is present in 70% of normal newborns. They are red, irregular, macular patches resultingfrom dilation of dermal capillaries and are usually found on thenape of the neck, the eyelids, and the glabella. Most of the faciallesions fade by 1 year of age, but lesions on the neck may persistfor life. Surveys of adult populations confirm the persistenceof the nuchal lesions in approximately 25% of the population. ERYTHEMA MULTIFORME, STEVENS-JOHNSON SYNDROME, AND TOXIC EPIDERMAL NECROLYSIS


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Pediatrics_Nelson. ERYTHEMA MULTIFORME, STEVENS-JOHNSON SYNDROME, AND TOXIC EPIDERMAL NECROLYSIS Erythema multiforme (EM), Stevens-Johnson syndrome (SJS),and toxic epidermal necrolysis (TEN) are acute hypersensitivity reactions characterized by cutaneous and mucosal necrosis.These syndromes represent a hypersensitivity reaction to a precipitating cause, usually infectious organisms or drugs. Thesedisorders were historically thought to represent a spectrum of the same disease process, and inconsistent use of these diseasenames led to further confusion. A consensus definition was published in 1993, and current literature favors that EM is distinct from the SJS/TEN spectrum of disease. The differential diagnosis of vesiculobullous eruptions is listed in Table 195-1. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com EM is a common, self-limiting, acute hypersensitivity syndrome characterized by the abrupt onset of round, deep red, well-demarcated macules and papules with a dusky gray or bullous center. The size may range from a few millimeters to a few centimeters, but most lesions are approximately 1 cm in diameter. The classic target lesion consists of three concentric rings; the outermost is red, the intermediate is white, and the center is a dusky red or purple. These can progress to edematous plaques or bullae. If blistering occurs, it is circumscribed Prodrome of fever, headache, malaise, sore throat, cough, vomiting, diarrhea Extensive epidermal necrosis with mucosal involvement Frequently related to drugs (e.g., sulfonamides, anticonvulsants) Nikolsky sign


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Pediatrics_Nelson. Generalized, tender erythema Nikolsky sign Occasionally associated with underlying infection such as osteomyelitis, septic arthritis, pneumonia Desquamation and moist erosions observed, especially in intertriginous areas More common in children younger than 5 years of age Herpes simplex Grouped vesicles on erythematous base May be recurrent at same site— lips, eyes, cheeks, hands Reactivated by fever, sunlight, trauma, stress Varicella Crops of vesicles on erythematous base (“dewdrops on rose petal”) Highly contagious May see multiple stages of lesions simultaneously Associated with fever Grouped vesicles on erythematous base limited to one or several adjacent dermatomes Thoracic dermatomes most commonly involved in children Usually unilateral Burning, pruritus Prodrome of fever, anorexia, sore throat Oval blisters in acral distribution, usually few in number Shallow, oral erosions on erythematous base in oral mucosa Highly infectious Peak incidence in late summer and in fall


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Pediatrics_Nelson. Erythema multiforme Target lesions on acral sites May have involvement of mucosal surfaces Associated with herpes simplex virus infection Urticaria pigmentosa Red-brown macules and papules; bullous lesions are rare Darier sign Lesions appear in infancy and spontaneously resolve in childhood Miliaria crystallina Clean, 1to 2-mm superficial vesicles occurring in crops Rupture spontaneously Intertriginous areas, especially neck and axillae Hereditary: epidermolysis bullosa, incontinentia pigmenti, epidermolytic hyperkeratosis Autoimmune: linear IgA disease, bullous pemphigoid, dermatitis herpetiformis Modified from Nopper AJ, Rabinowotz RG: Rashes and skin lesions. In Kliegman RM, editor: Practical Strategies in Pediatric Diagnosis and Therapy, Philadelphia, 1996, WB Saunders.


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Pediatrics_Nelson. Modified from Nopper AJ, Rabinowotz RG: Rashes and skin lesions. In Kliegman RM, editor: Practical Strategies in Pediatric Diagnosis and Therapy, Philadelphia, 1996, WB Saunders. and involves less than 10% of the body surface area. Cutaneous lesions are symmetrical and commonly involve acral areas such as the hands, feet, elbows, and knees. Involvement of the ocular, oral, and genital mucosa can be seen in some cases.


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Pediatrics_Nelson. Most EM cases in children are precipitated by herpes simplex virus infection, though the infection may no longer be apparent by the time EM develops. Mycoplasma pneumoniaeand other infectious organisms may also trigger EM. Symptomatic treatment is usually sufficient. Oral antihistamines help suppress pruritus, stinging, and burning. The use of systemic corticosteroids is controversial but may be considered for severe mucosal disease. Antiviral medications targeting herpes simplex virus do not alter the course of the EM, though children with recurrent EM may be candidates for prophylactic antivirals. The prognosis is excellent, with most lesions lasting no more than 2 weeks. Healing occurs without scarring.


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Pediatrics_Nelson. SJS, TEN, and SJS/TEN overlap are severe, life-threatening disorders thought to represent the same disease continuum. Theyare usually preceded by a prodrome of fever, malaise, and upperrespiratory symptoms 1 to 14 days before the onset of cutaneouslesions. Red macules appear suddenly and tend to coalesce intolarge patches, with a predominant distribution over the face andtrunk. Atypical targets may be present, causing diagnostic confusion initially with EM, although the atypical targets lack thecharacteristic three zones. Skin lesions evolve rapidly into bullaeand areas of necrosis. SJS is defined as epidermal detachment ofless than 10% of the body surface area, whereas SJS/TEN overlap has 10% to 30% and TEN has greater than 30% body surface area involvement. Any mucosal surface may be involved.The upper and lower lips are generally swollen and bright redwith erosions and hemorrhagic crusts, and the remainder of theoral mucosa may also be involved. Early in the disease process,there


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Pediatrics_Nelson. upper and lower lips are generally swollen and bright redwith erosions and hemorrhagic crusts, and the remainder of theoral mucosa may also be involved. Early in the disease process,there is bilateral conjunctival injection; however, this usuallyprogresses to conjunctival erosions. There may be erosions ofthe penile, vaginal, or perianal mucosa. Urogenital, esophageal,and tracheal surfaces may be involved in the most severe cases.


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Pediatrics_Nelson. Drugs and Mycoplasma pneumoniae infections are the most common causes of SJS/TEN in children. The most common drugs implicated are nonsteroidal anti-inflammatory drugs, sulfonamides, anticonvulsants, and antibiotics. Other precipitating factors are viral infections, bacterial infections, syphilis, and deep fungal infections. SJS/TEN can occur at any age. The diagnosis of SJS/TEN is clinical; there are no diagnostic tests. Confusion with EM, Kawasaki disease, and bacterial toxin-mediated diseases (scarlet fever, toxic shock syndrome, and staphylococcal scalded skin syndrome) may occur. Patients with Kawasaki disease have conjunctival injection and hyperemia of the mucous membranes. Necrosis of the mucosal surfaces does not occur; blistering, erosions, and severe crusting are not observed. The mucosal changes of staphylococcal scalded skin syndrome are minor, and frank erosions are not present. The blistering of the skin is more superficial and favors intertriginous regions.


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Pediatrics_Nelson. SJS/TEN is a serious illness with a mortality rate as high as35% for severe cases of TEN. Prompt discontinuation of theoffending agent is key. No controlled clinical trials regardingmedical therapy exist, though early initiation of intravenous immunoglobulin has been proposed. Supportive care is anotheressential component of therapy, and a multidisciplinary careteam is often necessary. Sepsis is the major cause of morbidityand mortality, so meticulous wound care is crucial, with stringent surveillance for cutaneous infections and use of antibiotics as warranted. Parenteral or nasogastric feeding should beinstituted early to accelerate the healing process. Careful fluidmanagement and monitoring of electrolytes are critical. Ocular complications are a major cause of long-term morbidity, soearly involvement of an ophthalmologist is important.


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Pediatrics_Nelson. Arthropods are common in the environment. Although many can bite or sting humans, only a few infest humans. Arachnids (mites) are the most common, parasitizing humans and animals by burrowing into the skin and depositing eggs within the skin. Available @ StudentConsult.com Scabies is caused by the mite Sarcoptes scabiei. The female mite burrows into the epidermis and deposits her eggs, which mature in 10 to 14 days. The disease is highly contagious because infested humans do not manifest the typical signs or symptoms for 3 to 4 weeks, facilitating transmission. An immunocompetent person with scabies typically harbors only 10 to 20 mites.


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Pediatrics_Nelson. The clinical presentation varies depending on the age of the patient, duration of infestation, and immune status of the patient. Severe and paroxysmal itching is the hallmark, with complaints of itching that is frequently worse than the eruption would suggest. Most children exhibit an eczematous eruption composed of red, excoriated papules and nodules. The classic linear papule or burrow is often difficult to find. Distribution is the most diagnostic finding; the papules are found in the axillae, umbilicus, groin, penis, instep of the foot, and web spaces of the fingers and toes (Fig. 196-1). Infants infested with scabies have diffuse erythema, scaling, and pinpoint papules. Pustules, vesicles, and nodules are much more common in infants and may be more diffusely distributed. The face and scalp usually are spared in adults and older children, but these areas are usually involved in infants. Nodular lesions may represent active infection or prolonged hypersensitivity lesions following


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Pediatrics_Nelson. scalp usually are spared in adults and older children, but these areas are usually involved in infants. Nodular lesions may represent active infection or prolonged hypersensitivity lesions following resolution of infestation. Immunocompromised or neurologically impaired persons may develop a severe form of the disease known as Norwegian or crusted scabies, with infestation of 2 million live mites at one time.


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Pediatrics_Nelson. Figure 196-1 Scabies (hand). The diagnosis of scabies can be confirmed by microscopic visualization of the mite, eggs, larvae, or feces in scrapings of papules or burrows examined under oil immersion. Skin biopsy is rarely necessary but may be useful if lesions have become nodular. Curative treatment is achieved by a 12-hour (overnight) application of permethrin 5% cream applied to the entire body. Because permethrin is not effective against the eggs, the treatment should be repeated 1 week later to kill any subsequently hatched larvae. All household members and close contacts should be treated simultaneously, even if asymptomatic. Bed linens, towels, and clothes worn for the previous 2 days before treatment should be machine-washed in hot water and machine-dried using high heat; heat is the most effective scabicide. Items that are not washable may be dry-cleaned or placed in a sealed plastic bag for 7 days.


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Pediatrics_Nelson. Secondary bacterial infection may occur but is uncommon. In contrast to the pediculoses, scabies is not a vector for infections. Pruritus may persist for 7 to 14 days after successful therapy because of a prolonged hypersensitivity reaction, which does not indicate treatment failure. Inadequate treatment or reinfestation should be suspected if new lesions develop after treatment. Three species of lice infest humans: Pediculus humanus capitis, the head louse; Pthirus pubis, the pubic louse or crab louse; and Pediculus humanus humanus (also known as Pediculus humanus corporis), the body louse. Lice are wingless insects 2 to 4 mm in length that cannot fly or jump. Transmission usually occurs by direct contact with another infested individual. Indirect spread through contact with fomites or personal belongings, such as hairbrushes, combs, or caps, is much less frequent.


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Pediatrics_Nelson. Pediculosis differs from scabies infestation in that the louse resides on the hair or clothing and intermittently feeds on the host by piercing the skin. The bite causes small urticarial papules and itching. Head lice live close to the skin and may live for 30 days, depositing 100 to 400 eggs as nits on hair shafts, usually within 6 mm of the scalp. Head lice are seen most frequently in early school-agechildren. Head lice infestations are unrelated to hygiene andare not more common among children with long hair orwith dirty hair. It is estimated that 6 to 12 million personsin the United States and 1% to 3% of persons in developedcountries are infested with head lice each year. In the UnitedStates, head lice infestation is rare among African Americansand may be more common in girls, which is attributed totheir tendency to play more closely with one another thanboys do.


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Pediatrics_Nelson. Pubic lice are transmitted by sexual contact. Their presence in children may be a sign of child abuse. Body lice are firm evidence of poor hygiene, such as infrequent washing and clothing changes. Itching, if present, is the primary symptom. Pediculosis capitis usually causes pruritus behind the ears or on the nape of the neck, or a crawling sensation in the scalp. Pediculosis pubis usually causes pruritus in the groin. Eyelash involvement in children may cause crusting and blepharitis. Pediculosis corporis causes pruritus that, because of repeated scratching, may result in lichenification or secondary bacterial infection. Excoriations and crusting, with or without associated regional lymphadenopathy, may be present.


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Pediatrics_Nelson. Infestation with the head louse may be asymptomatic and has little morbidity. The diagnosis can be confirmed by visualizing a live louse. A fine-toothed comb to trap lice is more effective than simply looking at the hair. Wet combing is more time-consuming, but dry combing produces static that may propel the lice away from the comb. Nits represent the outer casing of the louse ova. Viable nits have an intact operculum (cap) on the nonattached end and a developing louse within the egg. Brown nits located on the proximal hair shaft suggest active infestation. White nits located on the hair shaft 4 cm or farther from the scalp indicate previous infestation. Because nonviable nits can remain stuck in the hair for weeks to months after an infestation has resolved, many children with nits do not have active lice infestation.


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Pediatrics_Nelson. The treatment of head lice is controversial because of resistance to many established options. Over-the-counter permethrin (1%) and pyrethrin-based products (0.17% to 0.33%)are the first choices of therapy. Because 20% to 30% of eggsmay survive one treatment, a second treatment should beapplied in 7 to 10 days. Drug resistance is on the rise, andmalathion (0.5%) lotion may be used as an alternative forresistant cases. Everyone in the family should be checked for head lice and treated if live lice are found to reduce the risk of reinfestation. Bed linens, towels, and clothes worn for the previous 2 days before treatment should be machine-washed in hot water and machine-dried using high heat. Items that are not washable may be dry-cleaned or placed in a sealed plastic bag for 2 weeks. Brushes and combs should be soaked in dish detergent or rubbing alcohol for 1 hour. Rugs, furniture, mattresses, and car seats should be vacuumed thoroughly.


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Pediatrics_Nelson. Manual removal of nits after treatment is not necessary to prevent spread. Children treated for head lice should return to school immediately after completion of the first effective treatment or first wet combing, regardless of the presence of remaining nits. There is no evidence that no nit or nit-free policies reduce transmission of head lice. If required for return to school, nit removal is best achieved by wetting the hair and combing with a fine-toothed metal comb.


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Pediatrics_Nelson. Excoriations can become secondarily infected with skin bacteria, usually Staphylococcus and Streptococcus. The body louse functions as a vector for potentially serious infectious diseases, including epidemic typhus, caused by Rickettsia prowazekii; louse-borne relapsing fever, caused by Borrelia recurrentis; and trench fever, caused by Bartonella quintana.These louse-borne infections are rare in the United States. In contrast to body lice, head lice and pubic lice are not associated with transmission of other infections. Eichenfield LE, Esterly NB, Frieden IJ: Textbook of Neonatal Dermatology, ed 2, Philadelphia, 2008, Saunders Holland KE, Drolet BA: Infantile hemangioma, Pediatr Clin North Am 57:1069–1083, 2010 Krakowski AC, Eichenfield LF, Dohil MA: Management of atopic dermatitis in the pediatric population, Pediatrics 122:812–814, 2008 Paller AS, Mancini AJ: Hurwitz Clinical Pediatric Dermatology, ed 4, Philadelphia, 2011, Saunders


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Pediatrics_Nelson. Paller AS, Mancini AJ: Hurwitz Clinical Pediatric Dermatology, ed 4, Philadelphia, 2011, Saunders Schachner LA, Hansen RC: Pediatric Dermatology, ed 4, Philadelphia, 2011, Yan AC, Baldwin HE, Eichenfield LF, et al: Approach to pediatric acne treat ment: an update, Semin Cutan Med Surg 30:S16–S21, 2011 Kevin D. Walter and J. Channing Tassone 26 To care for the pediatric patient, one must understand the growth and development of the musculoskeletal system as well as common orthopedic terms (Table 197-1). Practitioners Bone growth center that has a muscular insertion but is not considered a growth plate (example: tibial tubercle)


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Pediatrics_Nelson. Bone growth center that has a muscular insertion but is not considered a growth plate (example: tibial tubercle) Arthroscopy Surgical exploration of a joint using an arthroscope Arthroplasty Surgical reconstruction of a joint Arthrotomy Surgical incision into a joint; an “open” procedure Deformation Changes in limb, trunk, or head due to mechanical force Dislocation Displacement of bones at a joint Equinus Plantar flexion of the forefoot, hindfoot, or entire foot Femoral Increased angulation of the femoral head and neck anteversion with respect to the frontal plane Malformation Defect in development that occurs during fetal life (example: syndactyly) Osteotomy Surgical division of a bone Pes cavus High medial arch of the foot Pes planus Flat foot Rotation, Inward rotation (toward midline)


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Pediatrics_Nelson. Rotation, Outward rotation (away from midline) external Subluxation Incomplete loss of contact between two joint surfaces Tibial torsion Rotation of the tibia in an internal or external fashion Valgus/ Angulation of a bone or joint in which the apex is valgum toward the midline (example: knock-knee) Varus/varum Angulation of a bone or joint in which the apex is away from the midline (example: bowlegs) should recognize common mechanisms for congenital and acquired orthopedic disorders (Table 197-2). The ends of the long bones contain a much higher proportion of cartilage in the skeletally immature child than in an adult (Figs. 197-1 and 197-2). The high cartilage content allows for a unique vulnerability to trauma and infection (particularly in the metaphysis).


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Pediatrics_Nelson. The physis is responsible for the longitudinal growth of thelong bones. Articular cartilage allows the ends of the bone toenlarge and accounts for growth of smaller bones, such as thetarsals. The periosteum can provide circumferential growth.Trauma, infection, nutritional deficiency (rickets), inborn errors of metabolism (mucopolysaccharidoses), and other metabolic disorders (renal tubular acidosis, hypothyroid) may affecteach of the growth processes and produce distinct aberrations. Figure 197-1 Schematic of long bone structure. Neurologic maturation, marked by achievement of developmental motor milestones, is important for normal musculoskeletal development (see Section 2). A neurologic disorder may cause a secondary musculoskeletal abnormality (e.g., extremity contractures in Duchenne muscular dystrophy). Thus, normal motor development must be included in the definition of a normal musculoskeletal system. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking Bowlegs and Knock-Knees The in utero position of the fetus can affect the angular and torsional alignment (temporary or permanent) of the skeletal system, especially of the lower extremity (Fig. 197-3). The newborn’s hips are externally rotated. Pes planus and genu varum are common. Infants are usually born with a flexed posture. This position usually decreases to neutral within the first 4 to 6 months. The foot is often flat and tucked under at birth; the ankle will be inverted and the forefoot is adducted when compared with the hindfoot. The lateral border of the foot must straighten out, even with dorsiflexion, to be considered secondary to in utero positioning. The head and neck may also be distorted by in utero positioning. The spine and upper extremities are less likely to be affected. By the age of 3 to 4 years, the effects of in utero positioning have usually resolved.


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Pediatrics_Nelson. Normal gait has a stance phase and swing phase; each legshould have symmetrical timing with each phase. The Figure 197-2 The ends of long bones at various ages. Lightly stippled areas represent cartilage composition, whereas heavily darkened areas are zones of ossification. (From Tachjidan MO: Congenital Dislocation of the Hip, New York, 1982, Churchill Livingstone, p 105.) stance phase represents 60% of the gait and begins with footcontact (usually the heel strike) and ends with the toe-off.During the swing phase (40%), the foot is off the ground.The gait cycle is the interval between stance phases on thesame limb. Toddlers will generally walk independently by 18 months of age. Their externally rotated gait is usually inconsistent, is characterized by short, rapid steps, and does not have the reciprocal arm swing. Gait coordination improves over time, with a normal gait usually achieved by the time a child enters elementary school. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com Limp In-Toeing, Out-Toeing, and Toe-Walking The Limping Child The differential diagnosis for a limping child is often categorized by age and presence or absence of a painful limp (Table 197-3). The gluteus medius muscle stabilizes thepelvis during the stance phase, preventing the pelvis fromdropping toward the leg in swing phase. An antalgic gait is a painful limp; the stance phase and stride of the affected limbare shortened to decrease the discomfort of weight bearingon the affected limb. The Trendelenburg gait has a normal stance phase, but excessive swaying of the trunk. Waddling gait refers to a bilateral decrease in function of the gluteusmuscles.


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Pediatrics_Nelson. Toe walking is a common complaint in early walkers. A physician should evaluate any child older than 3 years of age whostill toe walks. Although this is most likely habit, a neuromuscular disorder (cerebral palsy, tethered cord), Achilles tendoncontracture (heel cord tightness), or a leg-length discrepancyshould be considered. Differential Diagnosis of Limping in Children Early walker: 1 to 3 years of age Child: 3 to 10 years of age Developmental dysplasia of the hip Neuromuscular disorder Cerebral palsy Lower extremity length inequality Septic arthritis, osteomyelitis, myositis Transient monarticular synovitis Trauma Rheumatologic disorders Developmental dysplasia of the hip Legg-Calve-Perthes disease Lower extremity length inequality Neuromuscular disorder Cerebral palsy Muscular dystrophy (Duchenne) Adolescent: 11 years of age to maturity Septic arthritis, osteomyelitis, myositis Trauma Rheumatologic disorder Slipped capital femoral epiphysis: acute; unstable Malignancy


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Pediatrics_Nelson. Septic arthritis, osteomyelitis, myositis Trauma Rheumatologic disorder Slipped capital femoral epiphysis: acute; unstable Malignancy Slipped capital femoral epiphysis: chronic; stable Developmental dysplasia of the hip: acetabular dysplasia Lower extremity length inequality Neuromuscular disorder Fractures account for 10% to 15% of all childhood injuries.The anatomic, biomechanical, and physiologic differencesin children account for unique fracture patterns and management. Fracture terminology helps describe fractures(Table 198-1).


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Pediatrics_Nelson. The pediatric skeleton has a higher proportion of cartilage and a thicker, stronger, and more active periosteum, capable of producing a larger callus more rapidly than in an adult. The thick periosteum may decrease the rate of displaced fractures and stabilize fractures after reduction. Because of the higher proportion of cartilage, the skeletally immature patient can withstand more force before deformation or fracture than adult bone. As children mature into adolescence, the rate of healing slows and approaches that of adults. Buckle or torus fractures occur after compression of the bone; the bony cortex does not truly break. These fractures will typically occur in the metaphysis and are stable fractures that heal in approximately 4 weeks with immobilization. A common example is a fall onto an outstretched arm causing a buckle fracture in the distal radius.


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Pediatrics_Nelson. Complete fractures occur when both sides of bony cortex are fractured. This is the most common fracture and may be classified as comminuted, oblique, transverse, or spiral, depending on the direction of the fracture line. Greenstick fractures occur when a bone is angulated beyond the limits of plastic deformation. The bone fails on the tension side and sustains a bend deformity on the compression side. The force is insufficient to cause a complete fracture (Fig. 198-1). The bone fragments separate completely Incomplete The bone fragments are still partially joined Linear


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Pediatrics_Nelson. The bone fragments separate completely Incomplete The bone fragments are still partially joined Linear Referring to a fracture line that is parallel to the bone’s long axis Transverse Referring to a fracture line that is at a right angle to the bone’s long axis Oblique Referring to a fracture line that is diagonal to the bone’s long axis Spiral Referring to a twisting fracture Comminution A fracture that results in several fragments Compaction The bone fragments are driven into each other Angulation The fragments have angular malalignment Rotation The fragments have rotational malalignment Shortening The fractured ends of the bones overlap Open A fracture in which the bone has pierced the skin Bowing fractures demonstrate no fracture line evident on radiographs, but the bone is bent beyond its limit of plastic deformation. This is not a true fracture, but will heal with periosteal reaction. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com Fractures involving the growth plate constitute about 20% of all fractures in the skeletally immature patient. These fractures are more common in males (2:1 male-female ratio). The peak incidence is 13 to 14 years in boys and 11 to 12 years in girls. The distal radius, distal tibia, and distal fibula are the most common locations. Ligaments frequently insert onto epiphyses. Thus, traumatic forces to an extremity may be transmitted to the physis, which is not as biomechanically strong as the metaphysis; it may fracture with mechanisms of injury that may cause sprains in the adult. The growth plate is most susceptible to torsional and angular forces.


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Pediatrics_Nelson. Physeal fractures are described using Salter-Harris classification, which allows for prognostic information regarding premature closure of the growth plate and poor functional outcomes. The higher the type number, the more likely the patient will have complications. There are five main groups (Fig. 198-2):Type I: transverse fracture through the physis; growth disturbance is unusual Type II: fracture through a portion of the physis and metaphysis; most common type of Salter-Harris fracture (75%) Type III: fracture through a portion of the physis and epiphysis into the joint that may result in complication because of intra-articular component and because of disruption of the growing or hypertrophic zone of the physis Figure 198-1 The greenstick fracture is an incomplete fracture. (Modified from White N, Sty R: Radiological evaluation and classification of pediatric fractures, Clin Pediatr Emerg Med 3:94–105, 2002.)


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Pediatrics_Nelson. (Modified from White N, Sty R: Radiological evaluation and classification of pediatric fractures, Clin Pediatr Emerg Med 3:94–105, 2002.) Type IV: fracture through the metaphysis, physis, and epiphysis with a high risk of complicationType V: a crush injury to the physis with a poor functional Types I and II fractures can often be managed by closed reduction and do not require perfect alignment. A major exception is the type II fracture of the distal femur, which is associated with a poor outcome unless proper anatomic alignment is obtained. Types III and IV fractures require anatomic alignment for successful treatment. Type V fractures are rare and often result in premature closure of the physis.


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Pediatrics_Nelson. The majority of pediatric fractures can be managed with closed methods. Some fractures need closed reduction to improve alignment. Approximately 4% of pediatric fractures require internal fixation. Patients with open physes are more likely to require internal fixation if they have one of the following fractures:Displaced epiphyseal fracturesDisplaced intra-articular fracturesFractures in a child with multiple injuriesOpen fracturesUnstable fractures The goal of internal fixation is to improve and maintain anatomic alignment. This is usually done with Kirschner wires, Steinmann pins, and cortical screws with subsequent external immobilization in a cast until healing is satisfactory. After healing, the hardware is frequently removed to prevent incorporation into the callus and prevent physeal damage.


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Pediatrics_Nelson. External fixation without casting may be necessary for pelvic fractures causing hemodynamic instability. Fractures associated with soft tissue loss, burns, and neurovascular damage may benefit from external fixation. Fracture remodeling occurs because of a combination ofperiosteal resorption and new bone formation. Many pediatric fractures do not need perfect anatomic alignment for proper healing. Younger patients have greater potential for fracture remodeling. Fractures that occur in the meta-physis,near the growth plate, may undergo more remodeling. Fractures angulated in the plane of motion also remodel very well.Intra-articular fractures, angulated or displaced diaphysealfractures, rotated fractures, and fracture deformity not in theplane of motion tend not to remodel as well.


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Pediatrics_Nelson. Overgrowth occurs in long bones as the result of increased blood flow associated with fracture healing. Femoral fractures in children younger than 10 years of age will frequently overgrow 1 to 3 cm. This is the reason end-to-end alignment for femur and long-bone fractures may not be indicated. After 10 years of age, overgrowth is less of a problem, so end-to-end alignment is recommended. Fractures and injuries to the physis can result in premature closure. If it is a partial closure, the consequence may be an angular deformity. If it is a complete closure, limb shortening may occur. The most commonly affected locations are the distal femur and the distal and proximal tibia.


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Pediatrics_Nelson. Fractures and dislocations may damage adjacent blood vessels and nerves. The most common location is the distal humerus (supracondylar fracture) and the knee (dislocation and physeal fracture). It is necessary to perform and document a careful neurovascular examination distal to the fracture (pulse, sensory, and motor function). Compartment syndrome is an orthopedic emergency that results from hemorrhage and soft tissue swelling within the tight fascial compartments of an extremity. This can result in muscle ischemia and neurovascular compromise unless it is surgically decompressed. The most common sites are the lower leg (tibial fracture) and arm (supracondylar fracture).


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Pediatrics_Nelson. Affected patients have severe pain and will eventually have decreased sensation in the dermatomes supplied by the nerves located in the compartment. Swollen and tight compartments and pain with passive stretching are present. This can happen underneath a cast and may actually occur when a cast is applied too tightly. It is important to educate all patients with fractures on the signs of compartment syndrome and ensure that they realize it is an emergency. Figure 198-2 The types of growth plate injury as classified by Salter and Harris. See text for descriptions of types I to V. (From Salter RB, Harris WR: Injuries involving the epiphyseal plate, J Bone Joint Surg Am 45:587–622, 1963.)


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Pediatrics_Nelson. This is an oblique fracture of the distal tibia without a fibula fracture. There is often no significant trauma. Patients are usually 1 to 3 years old, but can be as old as 6 and present with limping and pain with weight bearing. There may be minimal swelling and pain. Initial radiographs do not always show the fracture; if symptoms persist, a repeat x-ray in 7 to 10 days may be helpful. Available @ StudentConsult.com Child abuse must always be considered in the differential diagnosis of a child with fractures, especially in those younger than 3 years (see Chapter 22). Common fracture patterns that should increase the index of suspicion include multiple fractures in different stages of radiographic healing, metaphyseal corner fractures (shaking), fractures too severe for the history, or fractures in nonambulatory infants. Although spiral fractures of long bones were historically considered pathognomic for abuse, they can be seen in nonabuse situations.


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Pediatrics_Nelson. When there is concern for child abuse, the child should have a full evaluation, which may include admission to the hospital. A thorough and well-documented physical examination should focus on soft tissue injuries, the cranium, and a funduscopic examination for retinal hemorrhages or detachment. A skeletal survey or a bone scan may be helpful in identifying other fractures.


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Pediatrics_Nelson. The hip is a ball (femoral head) and socket (acetabulum) joint that is important for skeletal stability. The femoral head and acetabulum are interdependent for normal growth and development. The femoral neck and head, which contain the capital femoral epiphysis, are intra-articular. The blood supply to this region is unique because the blood vessels are extraosseous and lie on the surface of the femoral neck, entering the epiphysis peripherally. Thus, the blood supply to the femoral head is vulnerable to trauma, infection, and other causes that may increase intra-articular pressure. Damage to the blood supply can lead to avascular necrosis.


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Pediatrics_Nelson. In developmental dysplasia of the hip (DDH), the hips atbirth may be dislocated or dislocatable. The femoral head andacetabulum develop from the same mesenchymal cells; by11 weeks’ gestation, the hip joint is formed. There are two typesof DDH: teratologic and typical. Teratologic dislocationsoccur early in utero and are usually associated with neuromuscular disorders (spina bifida, arthrogryposis). Typical dislocations occur in the neurologically normal infant and can occurbefore or after birth. The true incidence of DDH is unknown, but it may be as high as 1.5 cases per 1000 infants.


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Pediatrics_Nelson. Newborn infants have ligamentous laxity that, if significant enough in the hip, may lead to spontaneous dislocation and reduction of the femoral head. Persistence of this spontaneous pattern can lead to pathologic changes, such asflattening of the acetabulum, muscle contractures that limitmotion, and joint capsule tightening. The left hip is affectedthree times as often as the right hip, possibly because of inutero positioning. Physiologic risk factors for DDH include a generalized ligamentous laxity, perhaps from maternal hormones that are associated with pelvic ligament relaxation (estrogen and relaxin). Female infants are at higher risk (9:1); family history is positive in 20% of all patients with DDH.


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Pediatrics_Nelson. Other risk factors include breech presentation, firstbornchild (60%), oligohydramnios, and postnatal infant positioning. In breech presentations, the fetal pelvis is situated in thematernal pelvis. This can increase hip flexion and limit overall fetal hip motion, causing further stretching of the alreadylax joint capsule and exposing the posterior aspect of thefemoral head. The altered relationship between the acetabulum and femoral head causes abnormal acetabular development. Postnatal positioning of the hips in a tight swaddlewith the hips adducted and extended can displace the hip joint. Congenital muscular torticollis, metatarsus adductus, and clubfoot are associated with DDH. An infant with any of these three conditions should receive a careful examination of the hips.


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Pediatrics_Nelson. Congenital muscular torticollis, metatarsus adductus, and clubfoot are associated with DDH. An infant with any of these three conditions should receive a careful examination of the hips. Every newborn requires a screening physical examination forDDH; further evaluation through at least the first 18 months of life is part of the physical examination for toddlers. DDHevolves over time, so the examination may change as the patientages. The examination starts with inspection for asymmetricalthigh and gluteal folds with the hips and knees flexed. A relativeshortening of the femur with asymmetrical skin folds is a positive Galeazzi sign and indicates DDH. Range of motion shouldbe assessed with the pelvis stabilized and the child supine onthe examining table, not in the parent’s lap (Fig. 199-1). Hipabduction should easily reach or exceed 75°, and hip adductionshould reach 30°. Limitations may indicate contractures associated with DDH, especially decreased abduction.


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Pediatrics_Nelson. Normal at birth to 1 month of age Often normal, 1 to 9 months of age Figure 199-1 Hip abduction test. Place the infant supine, flex the hips 90°, and fully abduct the hips. Although the normal abduction range is broad, hip disease should be suspected in any patient who lacks more than 30° to 45° of abduction. (From Chung SMK: Hip Disorders in Infants and Children, Philadelphia, 1981, Lea & Febiger, p 69.) The Barlow test attempts to dislocate an unstable hip (Fig. 199-2). The examiner should stabilize the infant’s pelvis with one hand and grasp the abducted and flexed thigh in the other hand. The hip should be flexed to 90°. Next, begin to adduct the hip, while applying a posterior force to the anterior hip. A hip that can be dislocated in this method is readily felt (clunk feeling) and is a positive test. It may reduce spontaneously once the posterior force is removed, or the examiner may need to perform the Ortolani test.


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Pediatrics_Nelson. The Ortolani test may reduce a dislocated hip (Fig. 199-3).The examiner should stabilize the pelvis and hold the leg in the same method as for the Barlow test. The infant’s hip should be in 90° of flexion. Abduct the hip while applying anterior pressure to the posterior thigh. A positive test is the palpable reduction of the dislocation, which may be felt (clunk). After 2 months of age, the hip may develop muscular contractures, preventing positive Ortolani tests. These tests should be performed with only gentle force and done one hip at a time. The test may need to be repeated multiple times, as they can be difficult to interpret. A click, which is not pathologic, may occur from breaking the surface tension of the hip joint or snapping gluteal tendons.


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Pediatrics_Nelson. Bilateral fixed dislocations present a diagnostic dilemma because of the symmetry on exam. The Klisic test is useful in this situation; it is done by placing the third finger over the greater trochanter and the index finger over the anterior superior iliac spine, then drawing an imaginary line between the two. The line should point to the umbilicus in a normal child. However, in a dislocated hip, the greater trochanter is elevated, which causes the line to project lower (between the umbilicus and pubis). This test is helpful identifying bilateral DDH, which can otherwise be difficult to diagnose because of the symmetry found on examination. Older children with unrecognized DDH may present with limping. A patient with increased lumbar lordosis and a waddling gait may have an unrecognized bilateral DDH.


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Pediatrics_Nelson. Older children with unrecognized DDH may present with limping. A patient with increased lumbar lordosis and a waddling gait may have an unrecognized bilateral DDH. Figure 199-2 Barlow (dislocation) test. Reverse of Ortolani test. If the femoral head is in the acetabulum at the time of examination, the Barlow test is performed to discover any hip instability. A, The infant’s thigh is grasped as shown and adducted with gentle downward pressure. B, Dislocation is palpable as the femoral head slips out of the acetabulum. Diagnosis is confirmed with the Ortolani test.


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Pediatrics_Nelson. Figure 199-3 Ortolani (reduction) test. With the infant relaxed and content on a firm surface, the hips and knees are flexed to 90°. The hips are examined one at a time. The examiner grasps the infant’s thigh with the middle finger over the greater trochanter and lifts the thigh to bring the femoral head from its dislocated posterior position to opposite the acetabulum. Simultaneously the thigh is gently abducted, reducing the femoral head in the acetabulum. In a positive finding, the examiner senses reduction by a palpable, nearly audible clunk. Ultrasound is used for initial evaluation of infants with DDH. Ultrasonography is necessary for girls with a positive family history or breech presentation in both sexes. This should be obtainedafter 6 weeks of age to avoid confusion with physiologic laxity.Because the femoral head begins to ossify at 4 to 6 months of age,plain radiographs can be misleading until patients are older.


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Pediatrics_Nelson. The treatment of DDH is individualized and depends on the child’s age at diagnosis. The goal of treatment is a stable reduction that results in normal growth and development of the hip. If DDH is suspected, the child should be sent to a pediatric orthopedic specialist. The Pavlik harness is an effective treatment up to 6 months ofage. It provides hip flexion to just over 90° and limits adduction tono more than neutral. This positioning redirects the femoral headtoward the acetabulum. The hip must be reduced within 1 to 2weeks of beginning the Pavlik harness, although the infant willneed more time in the device. The Pavlik harness is successful in treating approximately 95% of dysplastic or subluxated hips, and80% successful for treatment of true dislocations. Persistently dislocated hips should not remain in a Pavlik harness for more than2 weeks for fear of iatrogenic acetabular damage. Patients failingthe Pavlik harness warrant treatment with an abduction orthosis.


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Pediatrics_Nelson. Children over 6 months or those who have failed nonoperative treatment should undergo closed reduction using a hip spica cast. This is done under general anesthesia; reduction is evaluated with an intraoperative arthrogram, then confirmed by postoperative computed tomography (CT) or magnetic resonance imaging (MRI). If closed reduction fails, open reduction is indicated. Patients over 18 months of age may require a pelvic and femoral osteotomy. The most important and severe complication of DDH is iatrogenic avascular necrosis of the femoral head. This can occur from excessive flexion or abduction during positioning of the Pavlik harness or hip spica cast. Infants under 6 months of age are at highest risk. Pressure ulcers can occur with prolonged casting. Redislocation or subluxation of the femoral head and residual acetabular dysplasia can occur. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com Transient synovitis, also known as toxic synovitis, is a common cause of limping in children. It is a diagnosis of exclusion, because septic arthritis and osteomyelitis of the hip must be excluded (see Chapters 117 and 118). The etiology of transient synovitis is uncertain, but possible causes are viral illness and hypersensitivity. Approximately 70% of children diagnosed with transient synovitis have an upper respiratory tract viral infection in the preceding 7 to 14 days. Biopsies have revealed nonspecific synovial hypertrophy. Hip joint aspirations, when necessary, are negative for bacterial culture or signs of bacterial infection. The mean age at onset is 6 years, with a range of 3 to 8 years. It is twice as common in male children.


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Pediatrics_Nelson. The mean age at onset is 6 years, with a range of 3 to 8 years. It is twice as common in male children. The patient or family will describe an acute onset of pain in the groin/hip, anterior thigh, or knee. Irritation of the obturator nerve can cause referred pain in the thigh and knee when the pathology is at the hip. Patients with transient synovitis are often afebrile, walk with a painful limp, and have normal to minimally elevated white blood cell count, C-reactive protein, and erythrocyte sedimentation rate compared with bacterial diseases of the hip (Table 199-1). Table 197-3 lists the differential diagnosis of a limping child. Anteroposterior and frog-leg radiographs of the hip are usually normal. Ultrasonography may reveal a joint effusion. It is mandatory to rule out septic arthritis in the presence of effusion with a joint aspiration and cell count.


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Pediatrics_Nelson. The mainstay of treatment is bed rest and minimal weight bearing until the pain resolves. Nonsteroidal anti-inflammatory medication is usually sufficient to decrease pain. Limiting strenuous activity and exercise for 1 to 2 weeks following recovery is helpful. Follow-up will help ensure that there is no deterioration. Lack of improvement necessitates further evaluation for more serious disorders. Available @ StudentConsult.com Elevated joint fluid cell count Afebrile Fever—temperature >38.5° C Leukocytosis Normal WBC count ESR >20 mm/hour Normal ESR and CRP Refusal to walk Painful limp Hip held in external rotation, Hip held normally abduction, and flexion CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; WBC, white blood cell. *Examples: Septic arthritis, osteomyelitis of hip.


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Pediatrics_Nelson. CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; WBC, white blood cell. *Examples: Septic arthritis, osteomyelitis of hip. Legg-Calve-Perthes disease (LCPD) is idiopathic avascular necrosis (osteonecrosis) of the capital epiphysis of the femoral head. The etiology is unclear, but it is likely caused by an interruption of the blood supply to the capital femoral epiphysis. There may be an associated hypercoagulability state (factor V Leiden). LCPD commonly presents in patients 3 to 12 years of age, with a mean age of 7 years. It is four to five times more common in boys. Patients may not present for several weeks because of minimaldiscomfort; the classic presentation is a child with an atraumatic, painless limp. There may be mild or intermittent hip/groin, anterior thigh, or knee pain. Decreased internal rotationand abduction with some discomfort, thigh muscle spasm, andanterior thigh muscular atrophy may be present. Patients havedelayed bone age.


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Pediatrics_Nelson. Anteroposterior and frog-leg radiographs of both hips are usually adequate for diagnosis and management. It is necessary to document the extent of the disease and follow its progression. MRI and bone scan are helpful to diagnose early LCPD. LCPD is usually a self-limited disorder that should be followed by a pediatric orthopedist. Initial treatment focuses on pain control and restoration of hip range of motion. The goal of treatment is prevention of complications, such as femoral head deformity and secondary osteoarthritis. Containment is important in treating LCPD; the femoral head is contained inside the acetabulum, which acts like a mold for the capital femoral epiphysis as it reossifies. Nonsurgical containment uses abduction casts and orthoses, whereas surgical containment is accomplished with osteotomies of the proximal femur and pelvis.


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Pediatrics_Nelson. The short-term prognosis is determined by the magnitude of the femoral head deformity after healing has completed. It is improved by early diagnosis, good follow-up, and compliance with the treatment plan. Older children and children with a residual femoral head deformity are more likely to develop osteoarthritis (OA). The incidence of OA in patients who developed LCPD after 10 years of age is close to 100%; it is negligible in children with onset before 5 years of age. Patients between 6 and 9 years of age have a risk of OA of less than 40%. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com Slipped capital femoral epiphysis (SCFE) is a common adolescent hip disorder that is an orthopedic emergency. The incidence is 10.8 per 100,000, and it is slightly higher in males. African-American and Hispanic populations are at higher risk. Approximately 20% of patients with SCFE will have bilateral involvement at presentation, and another 20% to 40% may progress to bilateral involvement. The average age is 10 to 16 years, with a mean of 12 years in boys and 11 years in girls. Additional risk factors for SCFE include obesity, trisomy 21, and endocrine disorders (hypothyroid, pituitary tumor, growth hormone deficiency).


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Pediatrics_Nelson. SCFE is classified as stable or unstable. Unstable patients refuse to ambulate even with crutches. Stable patients have an antalgic gait. SCFE can also be characterized as acute (symptoms less than 3 weeks) or chronic (symptoms over 3 weeks). Acute-on-chronic SCFE is seen when more than 3 weeks of symptoms are accompanied by an acute exacerbation of pain and difficulty/inability to bear weight.


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Pediatrics_Nelson. The presentation is variable, based on severity and type of slip. Patients will often report hip or knee pain, limp or inability to ambulate, and decreased hip range of motion. There may or may not be a traumatic event. Any knee pain mandates an examination of the hip, as hip pathology can cause referred pain to the anterior thigh and knee along the obturator nerve. The patient usually holds the affected extremity in external rotation. As the hip is flexed, it will progressively externally rotate. There is usually a limitation of internal rotation, but there may also be a loss of flexion and abduction. If the patient can bear weight, it is typically an antalgic gait with the affected leg in external rotation. It is important to examine both hips to determine bilateral involvement.


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Pediatrics_Nelson. Anteroposterior and frog-leg radiographs are indicated.Patients with known SCFE or with a high index of suspicionshould not undergo frog-leg lateral radiographs. Instead, a crosstable lateral radiograph reduces the risk of iatrogenic progression. The earliest sign of SCFE is widening of the physis withoutslippage (preslip condition). Klein’s line (Fig. 199-4) is helpfulin assessing the anteroposterior radiograph for SCFE. The slippage can be classified radiographically as type I (0% to 33% displacement), type II (34% to 50%), or type III (>50%). The likelihood of complications increases with degree of displacement.


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Pediatrics_Nelson. Patients with SCFE should be immediately made non–weight bearing and referred to a pediatric orthopedist. The goal is to prevent further slippage, enhance physeal closure, and minimize complications, which is usually accomplished with internal fixation in situ with a single cannulated screw. More severe cases may require surgical hip dislocation and reduction to realign the epiphysis. There is controversy surrounding the prophylactic fixation of the nonaffected side. Assessment for endocrine disorders is important, particularly in children outside the range of 10 to 16 years of age.


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Pediatrics_Nelson. Figure 199-4 Slipped capital femoral epiphysis (SCFE). A, Anteroposterior radiograph reveals a widened physis (small arrows) and decreased height of the epiphysis on the left. In addition, there is loss (large arrow) of the Capener triangle (c) (normal double density of the medial metaphysis superimposed on the posterior acetabular rim on right) and an abnormal lateral femoral neck line (normal on right). B, Frog, lateral view confirms the inferomedial position of the SCFE. (From Blickman H: Pediatric Radiology, the Requisites, ed 2, St Louis, 1998, Mosby, p 244.)


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Pediatrics_Nelson. The two most serious complications of SCFE are chondrolysis and avascular necrosis. Chondrolysis is destruction of the articular cartilage. It is associated with more severe slips and with intra-articular penetration of operative hardware. This can lead to severe osteoarthritis (OA) and disability. Avascular necrosis occurs when there is a disruption of the blood supply to the capital femoral epiphysis. This usually happens at the time of injury, but may occur during forced manipulation of an unstable slip. Avascular necrosis may occur in up to 50% of unstable SCFEs and may lead to OA.


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Pediatrics_Nelson. Torsional (in-toeing and out-toeing) and angular (physiologic bowlegs and knock knees) variations in the legs are common reasons that parents seek medical attention for their child. Most of these concerns are physiologic and resolve with normal growth. Understanding the natural history allows physicians to reassure the family and to identify nonphysiologic disorders that necessitate further intervention. Physiologic disturbances are referred to as variations; pathologic disturbances are called deformities. The femur is internally rotated (anteversion) about 30° at birth, decreasing to about 10° at maturity. The tibia begins with up to 30° of internal rotation at birth and can decrease to a mean of 15° at maturity. Torsional variations should not cause a limp or pain. Unilateral torsion raises the index of suspicion for a neurologic (hemiplegia) or neuromuscular disorder. Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking


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Pediatrics_Nelson. Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking Internal femoral torsion or femoral anteversion is the most common cause of in-toeing in children 2 years or older (Table 200-1). It is at its worst between 4 and 6 years of age, and then resolves. It occurs twice as often in girls. Many cases are associated with generalized ligamentous laxity. The etiology of femoral anteversion is likely congenital and is common in individuals with abnormal sitting habits such as W-sitting.


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Pediatrics_Nelson. Clinical Manifestations. The family may give a history of W-sitting, and there may be a family history of similar concerns when the parents were younger. The child may have kissing kneecaps due to increased internal rotation of the femur. While walking, the entire leg will appear internally rotated, and with running the child may appear to have an egg-beatergait where the legs flip laterally. The flexed hip will have internal rotation increased to 80° to 90° (normal 60° to 70°) and external rotation limited to about 10°. Radiographic evaluation is usually not indicated. Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking


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Pediatrics_Nelson. Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking FIGURE 200-1 Thigh-foot angle measurement. The thigh-foot angle is useful for assessment of tibial torsion. The patient lies prone, with knees flexed to 90°. The long axis of the thigh is compared to the long axis of the foot to determine the thigh-foot angle. Negative angles are associated with internal tibial torsion, and positive angles are associated with external tibial torsion. This is the most common cause of in-toeing in a child younger than 2 years old. When it is the result of in utero positioning, it may be associated with metatarsus adductus.


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Pediatrics_Nelson. This is the most common cause of in-toeing in a child younger than 2 years old. When it is the result of in utero positioning, it may be associated with metatarsus adductus. Clinical Manifestations. The child will present witha history of in-toeing. The degree of tibial torsion may bemeasured using the thigh-foot angle (Fig. 200-1). Thepatient lies prone on a table with the knee flexed to 90°.The long axis of the foot is compared with the long axis of the thigh. An inwardly rotated foot represents a negativeangle and internal tibial torsion. If follow-up is warranted,measurements should be done at each visit to document improvement. Treatment of In-toeing


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Pediatrics_Nelson. Treatment of In-toeing The mainstay of management is to identify patients who have pathologic reasons for in-toeing and reassurance and follow-up to document improvement for patients with femoral anteversion and internal tibial torsion. It can take until 7 to 8 years of age for correction, so it is important to inform families of the appropriate timeline. Braces (Denis Browne splint) do not improve these conditions. Fewer than 1% of all patients with in-toeing will need surgical intervention because of functional disability or cosmetic appearance. Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking


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Pediatrics_Nelson. Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking FIGURE 200-2 Bowleg and knock-knee deformities. A, Bowleg deformity. Bowlegs are referred to as varus angulation (genu varum) because the knees are tilted away from the midline of the body. B, Knock-knee or valgus deformity of the knees. The knee is tilted toward the midline. (From Scoles P: Pediatric Orthopedics in Clinical Practice, Chicago, 1982, Year Book Medical Publishers, p 84.)


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Pediatrics_Nelson. External tibial torsion is the most common cause of out-toeingand may be associated with a calcaneovalgus foot (see Chapter201). This is often related to in utero positioning. It may improveover time, but because the tibia rotates externally with age, external tibial torsion can worsen. It may be an etiologic factor forpatellofemoral syndrome, especially when combined with femoral anteversion. Treatment is usually observation and reassurance, but patients with dysfunction and cosmetic concerns maybenefit from surgical intervention. Available @ StudentConsult.com The majority of patients who present with knock-knees (genu valgum) or bowlegs (genu varum) are normal (Fig. 200-2).Infants are born with maximum genu varum. The lower extremity straightens out around 18 months of age. Children typicallyprogress to maximal genu valgum around 4 years. The legs areusually straight to a slight genu valgum in adulthood.


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Pediatrics_Nelson. It is important to inquire about family history and assessoverall height. A child who is 2 standard deviations belownormal with angular deformities may have skeletal dysplasia. Dietary history should be obtained, as rickets (see Chapter 31) may cause angular deformities. For genu valgum,following the intermalleolar distance (distance betweenthe two tibial medial malleoli with the knees touching) isused. Measurement of the intercondylar distance (the distance between the medial femoral condyles with the medialmalleoli touching) is used for genu varum. These measurements track improvement or progression. When obtaining radiographs, it is important to have the patella, not the feet,facing forward. In the child with external tibial torsion,having the feet facing forward gives the false appearance ofbowlegs. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com Physiologic knock-knees are most common in 3to 4-year-oldsand usually resolve between 5 and 8 years of age. Patients withasymmetrical genu valgum or severe deformity may have underlying disease causing their knock-knees (e.g., renal osteodystrophy, skeletal dysplasia). Treatment is based on reassurance ofthe family and patient. Surgical intervention may be indicatedfor severe deformities, gait dysfunction, pain, and cosmesis. Available @ StudentConsult.com Physiologic bowlegs are most common in children older than 18 months with symmetrical genu varum. This will generallyimprove as the child approaches 2 years of age. The most important consideration for genu varum is differentiating betweenphysiologic genu varum and Blount disease (tibia vara). Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com Tibia vara is the most common pathologic disorder associated with genu varum. It is characterized by abnormal growth of the medial aspect of the proximal tibial epiphysis, resulting in a progressive varus deformity. Blount disease is classified according to age of onset:Infantile (1 to 3 years)Juvenile (4 to 10 years)Adolescent (>11 years) Late-onset Blount disease is less common than infantile disease. The cause is unknown, but it is felt to be secondary to growth suppression from increased compressive forces across the medial knee. Infantile tibia vara is more common in African Americans, females, and obese patients. Many patients were early walkers. Nearly 80% of patients with infantile Blount disease have bilateral involvement. It is usually painless. The patients will often have significant internal tibial torsion and lower extremity leg-length discrepancy. There may also be a palpable medial tibial metaphyseal beak.


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Pediatrics_Nelson. Late-onset Blount disease is more common in African Americans, males, and markedly obese patients. Only 50% have bilateral involvement. The initial presentation is usually painful bowlegs. Late-onset Blount disease is usually not associated with palpable metaphyseal beaking, significant internal tibial torsion, or significant leg-length discrepancy. Weight-bearing anteroposterior and lateral radiographs of both legs are necessary for the diagnosis of tibia vara. Fragmentation, wedging, and beak deformities of the proximal medial tibia are the major radiologic features of infantile Blount disease. In late-onset Blount disease, the medial deformity may not be as readily noticeable. It can be very difficult to tell the difference between physiologic genu varum and infantile Blount disease on radiographs in patients younger than 2 years of age.


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Pediatrics_Nelson. Once the diagnosis of Blount disease is confirmed, treatment should begin immediately. Orthotics to unload the medial compressive forces can be used in children younger than 3 years of age with a mild deformity. Compliance with this regimen can be difficult. Nonoperative management of more severe Blount disease is contraindicated. Any patient older than 4 years should undergo surgical intervention. Patients with moderate to severe deformity and patients who fail orthotic treatment also require surgical intervention. Proximal tibial valgus osteotomy with fibular diaphyseal osteotomy is the usual procedure performed. Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking Leg-length discrepancy (LLD) is common and may be due to differences in the femur, tibia, or both bones. The differential diagnosis is extensive, but common causes are listed in Table 200-2. The majority of the lower extremity growth comes from the distal femur (38%) and the proximal tibia (27%).


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Pediatrics_Nelson. Clinical measurements using bony landmarks (anterior superior iliac spine to medial malleolus) are inaccurate. The teloradiograph is a single radiograph of both legs that can be done in very young children. The orthoradiograph consists of three slightly overlapping exposures of the hips, knees, and ankles. The scanogram consists of three standard radiographs of the hips, knees, and ankles with a ruler next to the extremities. A Developmental Developmental dysplasia of the hip (DDH) Legg-Calve-Perthes disease (LCPD) Neuromuscular Hemiplegia Disuse secondary to developmental delay Infectious Physeal injury secondary to osteomyelitis Tumors Fibrous dysplasia Physeal injury secondary to irradiation or neoplastic infiltration Overgrowth


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Pediatrics_Nelson. Infectious Physeal injury secondary to osteomyelitis Tumors Fibrous dysplasia Physeal injury secondary to irradiation or neoplastic infiltration Overgrowth Trauma Physeal injury with premature closure Malunion (shortening of extremity) Overgrowth of healing fracture computed tomography (CT) scanogram is the most accurate measure of LLD, but also has the highest radiation exposure. Technology such as EOS/slot scanning is an extremely accurate, reduced-radiation alternative to CT scan. The measured discrepancy is followed using Moseley and Green-Anderson graphs.


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Pediatrics_Nelson. Treating LLD is complex. The physician must take into account the estimated adult height, discrepancy measurements, skeletal maturity, and the psychological aspects of the patient and family. LLD greater than 2 cm usually requires treatment. Shoe lifts can be used, but they will often cause psychosocial problems for the child and may make the shoes heavier and less stable. Surgical options include shortening of the longer extremity, lengthening of the shorter extremity, or a combination of the two procedures. Discrepancies less than 5 cm are treated by epiphysiodesis (surgical physeal closure) of the affected side, whereas discrepancies greater than 5 cm are treated by lengthening. Current use of removable implants, which permit growth modulation without permanent impact on growth plates, has allowed for early and more accurate treatment. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com The knee joint is constrained by soft tissues rather than the usual geometric fit of articulating bones. The medial and lateral collateral ligaments as well as the anterior and posterior cruciate ligaments maintain knee stability. Weight and force transmission can cross articular cartilage and the meniscus. Pull of vastus lateralis vastus intermedialis rectus femoris Femur Pull of vastus medialis PATELLA Pull of patellar tendon FIGURE 200-3 Diagram of the knee extensor mechanism. The major force exerted by the quadriceps muscle tends to pull the patella laterally out of the intercondylar sulcus. The vastus medialis muscle pulls medially to keep the patella centralized. (Modified from Smith JB: Knee problems in children, Pediatr Clin North Am 33:1439, 1986.) The patellofemoral joint is the extensor mechanism of the knee and a common site of injury in the adolescent (Fig. 200-3).


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Pediatrics_Nelson. The patellofemoral joint is the extensor mechanism of the knee and a common site of injury in the adolescent (Fig. 200-3). Knee effusion or swelling is a common sign of injury. Whenthe fluid accumulates rapidly after an injury, it is usually ahemarthrosis (blood in the joint) and may indicate a fracture,ligamentous disruption (often of the anterior cruciate ligament[ACL]), or meniscus tear. Unexplained knee effusion mayoccur with arthritis (septic, Lyme disease, viral, postinfectious,juvenile idiopathic arthritis, systemic lupus erythematosus).It may also occur as a result of overactivity and hypermobilejoint syndrome (ligamentous laxity). An aspiration and laboratory evaluation of unexplained effusion can help expedite adiagnosis.


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Pediatrics_Nelson. Each meniscus is normally semilunar in shape; rarely thelateral meniscus will be disk shaped. A normal meniscus isattached at the periphery and glides anteriorly and posteriorlywith knee motion. The discoid meniscus is less mobile and may tear more easily. When there is inadequate posterolateral attachment, the discoid meniscus can displace anteriorlywith knee flexion, causing an audible click. Most commonly,patients will present in late childhood or early adolescenceafter an injury with knee pain and swelling. The anteroposterior radiographs can show increased joint space and asquared-off appearance of the lateral femoral condyle; magnetic resonance imaging (MRI) can confirm the diagnosis.Treatment is usually arthroscopic excision of tears and reshaping of the meniscus.


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Pediatrics_Nelson. A popliteal cyst (Baker cyst) is commonly seen in themiddle childhood years. The cause is the distension ofthe gastrocnemius and semimembranous bursa alongthe posteromedial aspect of the knee by synovial fluid. Inadults, Baker cysts are associated with meniscus tears. In childhood, the cysts are usually painless and benign. Theyoften spontaneously resolve, but it may take several years.Knee radiographs are normal. The diagnosis can be confirmed by ultrasound. Treatment is reassurance, becausesurgical excision is indicated only for progressive cysts or cysts that cause disability. Available @ StudentConsult.com


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Pediatrics_Nelson. Osteochondritis dissecans (OCD) most commonly involves theknee. It occurs when an area of bone adjacent to the articularcartilage suffers a vascular insult and separates from the adjacentbone. It most commonly affects the lateral aspect of the medialfemoral condyle. Patients may complain of knee pain or swelling.The lesions can be seen on anteroposterior, lateral, and tunnelview radiographs. MRI can be helpful in determining the extentof the injury. In young patients with intact articular cartilage,the lesion will often revascularize and heal with rest from activities. The healing process may take several months and requiresradiographic follow-up to document healing. With increasingage, the risk for articular cartilage damage and separation of thebony fragment increases. Older patients are more likely to needsurgical intervention. Any patient with a fracture of the articularcartilage will not improve without surgical intervention. Patientswith OCD should be referred to a specialist.


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Pediatrics_Nelson. Available @ StudentConsult.com Osgood-Schlatter disease is a common cause of knee pain at the insertion of the patellar tendon on the tibial tubercle. The stress from a contracting quadriceps muscle is transmitted through the developing tibial tubercle, which can cause a microfracture or partial avulsion fracture in the ossification center. It usually occurs after a growth spurt and is more common in boys. The age at onset is typically 11 years for girls and 13 to 14 years for boys. Patients will present with pain during and after activity as well as have tenderness and local swelling over the tibial tubercle. Radiographs may be necessary to rule out infection, tumor, or avulsion fracture.


Pediatrics_Nelson

Pediatrics_Nelson. Rest and activity modification are paramount for treatment. Pain control medications and icing may be helpful. Lower extremity flexibility and strengthening exercise programs are important. Some patients may require immobilization. The course is usually benign, but symptoms frequently last 1 to 2 years. Complications can include bony enlargement of the tibial tubercle and avulsion fracture of the tibial tubercle. Available @ StudentConsult.com


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Pediatrics_Nelson. Available @ StudentConsult.com The patellofemoral joint is a complex joint that dependson a balance between restraining ligaments of the patella,muscular forces around the knee, and alignment for normalfunction. The interior surface of the patella has a V-shapedbottom that moves through a matching groove in the femurcalled the trochlea. When the knee is flexed, the patellarligaments and the majority of the muscular forces pullingthrough the quadriceps tendon move the patella in a lateraldirection. The vastus medialis muscle counteracts the lateral motion, pulling the patella toward the midline. Problemswith function of this joint usually result in anterior kneepain.


Pediatrics_Nelson

Pediatrics_Nelson. Idiopathic anterior knee pain is a common complaint inadolescents. It is particularly prevalent in adolescent femaleathletes. Previously, this was referred to as chondromalaciaof the patella, but this term is incorrect as the joint surfacesof the patella are normal. It is now known as patellofemoral pain syndrome (PFPS). The patient will present withanterior knee pain that worsens with activity, going up anddown stairs, and soreness after sitting in one position for an extended time. There is usually no associated swelling.The patient may complain of a grinding sensation underthe kneecap. Palpating and compressing the patellofemoral joint with the knee extended elicits pain. Patients oftenhave weak hip musculature or poor flexibility in the lower extremities. Radiographs are rarely helpful but may be indicated to rule out other diagnoses such as osteochondritisdissecans.


Pediatrics_Nelson

Pediatrics_Nelson. Treatment is focused on correcting the biomechanical problems that are causing the pain. This is usually done using an exercise program emphasizing hip girdle and vastus medialis strengthening with lower extremity flexibility. Anti-inflammatory medication, ice, and activity modifications may also be helpful. Persistent cases should be referred to an orthopedic or sports medicine specialist.


Pediatrics_Nelson

Pediatrics_Nelson. One must exclude recurrent patellar subluxation and dislocation when evaluating a patient with PFPS. Acute traumatic dislocation will usually cause significant disability and weight bearing seen in an initial dislocation. Patients with recurrent dislocations often have associated ligamentous laxity, genu valgum, and femoral anteversion. The initial treatment is nonoperative and may involve a brief period of immobilization, followed by an aggressive physical therapy program designed to strengthen the quadriceps and improve function of the patellofemoral joint. Continued subluxation or recurrent dislocation is failure of this treatment plan, and surgical repair is usually necessary.


Pediatrics_Nelson

Pediatrics_Nelson. In newborns and non–weight-bearing infants, the difference between posturing and deformity is important. Posturing is the habitual position in which the infant holds the foot; passive range of motion is normal. Deformity produces an appearance similar to posturing, but passive motion is restricted. Most pediatric foot disorders are painless. Foot pain is more common in older children (Table 201-1). Available @ StudentConsult.com In-Toeing, Out-Toeing, and Toe-Walking A clubfoot deformity involves the entire leg, not just thefoot. It affects 1 in 1000 newborns and is bilateral in one half of cases. The tarsals in the affected foot are hypoplastic;the talus is most affected. The muscles of the limb are hypo-plastic because of the abnormal tarsal interactions, whichleads to a generalized limb hypoplasia, mainly affectingand shortening the foot. There is usually atrophy of the calfmusculature.


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Pediatrics_Nelson. Family history is important. Club foot can be congenital, teratologic, or positional. Although congenital clubfoot (75% of all cases) is usually an isolated abnormality, every infant should be assessed for developmental dysplasia of the hip. Teratologic clubfoot is associated with a neuromuscular disorder, such as myelomeningocele, arthrogryposis, or other syndromes. Positional clubfoot is a normal foot that was held in the deformed position in utero. The diagnosis is seldom confused with other disorders (Fig. 201-1). The presence of clubfoot should prompt a careful search for other abnormalities. The infant will have hindfoot equinus and varus, forefoot adduction, and varying degrees of rigidity. All are secondary to the abnormalities of the talonavicular joint. Calf atrophy and foot shortening are more noticeable in older children.


Pediatrics_Nelson

Pediatrics_Nelson. In infants, radiographs and advanced imaging are rarely necessary for assessment because their tarsals have incomplete ossification. The navicular ossifies at about 3 years of age for girls and 4 years for boys. As children age, radiographs can be used to follow the tibial calcaneal and lateral talocalcaneal angles and to assess navicular positioning.


Pediatrics_Nelson

Pediatrics_Nelson. 0 to 6 years Poorly fitting shoes Fracture Puncture wound Foreign body Osteomyelitis Cellulitis Juvenile idiopathic arthritis Hair tourniquet Leukemia 6 to 12 years Poorly fitting shoes Trauma (fracture, sprain) Juvenile idiopathic arthritis Puncture wound Sever disease Accessory tarsal navicular Hypermobile flatfoot Oncologic (Ewing sarcoma, leukemia) 12 to 18 years Poorly fitting shoes Stress fracture Trauma (fracture, sprain) Foreign body Ingrown toenail Metatarsalgia Plantar fasciitis Achilles tendinopathy Accessory ossicles (navicular, os trigonum) Tarsal coalition Avascular necrosis of metatarsal (Freiberg infarction) or navicular (Kohler disease) Plantar warts FIGURE 201-1 Clinical picture demonstrating clubfoot deformity. (From Kliegman RM, Behrman, RE, Jenson HB, et al: Nelson’s Textbook of Pediatrics, ed 18, Philadelphia, 2007, Saunders, p 2778.)


Pediatrics_Nelson

Pediatrics_Nelson. FIGURE 201-1 Clinical picture demonstrating clubfoot deformity. (From Kliegman RM, Behrman, RE, Jenson HB, et al: Nelson’s Textbook of Pediatrics, ed 18, Philadelphia, 2007, Saunders, p 2778.) The goal of treatment is to correct the deformity and preserve mobility. Nonoperative treatment involves the Ponseti method of serial casting. The Ponseti method also relies on a percutaneous tenotomy of the Achilles tendon to help correct the equinus deformity. FIGURE 201-2 Clinical picture of metatarsus adductus with a nor-mal foot on opposite side. (From Kliegman RM, Behrman, RE, Jenson HB, et al: Nelson’s Textbook of Pediatrics, ed 18, Philadelphia, 2007, Saunders, p 2777.) About 20% of patients will require an anterior tibialis tendon transfer in early childhood. Rarely, more aggressive surgical procedures may need to be done. Complications of untreated clubfoot include severe disability. Complications of treated clubfoot include recurrence and stiffness. Available @ StudentConsult.com