10.5826/dpc.1304a253
Introduction: Seborrheic keratoses (SK), are very common benign skin lesions, which may increase in number and size with age.
Objective: The aim of the study was to assess any differences seen in seborrheic keratoses in relation to different skin types (ST) and lesion location.
Methods: This was a retrospective observational study of 10-months period, based on dermoscopic images of seborrheic keratoses and patient history recorded in database. Patients were categorized according to their age, sex, skin type, and location of SK.
Results: The frequency of SK remained high on the back for skin type 1, 2, 3 and 4. This same trend was also seen on the face and chest.  In skin type 3 we saw a reversal of distribution of SK, the highest frequency remained on the back, and this was followed by the chest rather than the face. In skin type 5 and 6, the nature of the distribution of SK was more facial,
Conclusions:  In summary our study shows that SK are more commonly seen in males than in females, they tend to dominate in sun exposed sites especially the back and the face. Both the smaller and larger sized SK dominated in ST 1 and 2. The lighter to darker shades of colour seen in seborrheic keratoses varied in accordance with the skin type, with lighter coloured SK being seen more in lighter skin types as compared to darker skin types, whereas bluish coloured SK were seen in all skin types except ST 1.
text/xml
2160-9381
2624
en
Giuseppe Argenziano
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
skin type
Clinical and Dermatoscopic Features of Seborrheic Keratoses According to Skin Types: A Retrospective Study
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Original Article
2023-10-31
2022-06-07
2023-10-31
2024-01-16
e2023253
Dermatol Pract Concept
Introduction: Seborrheic keratoses (SK), are very common benign skin lesions, which may increase in number and size with age.
Objective: The aim of the study was to assess any differences seen in seborrheic keratoses in relation to different skin types (ST) and lesion location.
Methods: This was a retrospective observational study of 10-months period, based on dermoscopic images of seborrheic keratoses and patient history recorded in database. Patients were categorized according to their age, sex, skin type, and location of SK.
Results: The frequency of SK remained high on the back for skin type 1, 2, 3 and 4. This same trend was also seen on the face and chest.  In skin type 3 we saw a reversal of distribution of SK, the highest frequency remained on the back, and this was followed by the chest rather than the face. In skin type 5 and 6, the nature of the distribution of SK was more facial,
Conclusions:  In summary our study shows that SK are more commonly seen in males than in females, they tend to dominate in sun exposed sites especially the back and the face. Both the smaller and larger sized SK dominated in ST 1 and 2. The lighter to darker shades of colour seen in seborrheic keratoses varied in accordance with the skin type, with lighter coloured SK being seen more in lighter skin types as compared to darker skin types, whereas bluish coloured SK were seen in all skin types except ST 1.
Giuseppe Argenziano
2023/10/31
10.5826/dpc.1304a253
e2023253
Dermatology Unit, Department of Mental and Physical Health and Preventive medicine, University of Campania Luigi Vanvitelli Naples, Italy.
2160-9381
skin type
en
e2023253
Yeatman JM, Kilkenny M, Marks R. The prevalence of seborrhoeic keratoses in an Australian population: does exposure to sunlight play a part in their frequency? Br J Dermatol. 1997;137(3):411-414. PMID: 9349339.
Clinical and Dermatoscopic Features of Seborrheic Keratoses According to Skin Types: A Retrospective Study
https://dpcj.org/index.php/dpc/article/download/2624/2370
 Clinical and Dermatoscopic Features of Seborrheic
          Keratoses According to Skin Types:
                A Retrospective Study
                             Sadia Ammad1, Gaetano Licata2, Gabriella Brancaccio3,
                                    Elvira Moscarella3, Giuseppe Argenziano3


1 Dermatology Department, Ashford and St Peter’s NHS Trust, St Peter’s Hospital, Chertsey, United Kingdom
2 Dermatology Unit, San Antonio Abate Hospital, Trapani, Italy
3 Dermatology Unit, Department of Mental and Physical Health and Preventive medicine, University of Campania Luigi Vanvitelli, Naples,
  Italy



Key words: seborrheic keratoses, dermoscopy, skin type
Citation: Ammad S, Licata G, Brancaccio G, Moscarella E, Argenziano G. Clinical and Dermatoscopic features of Seborrheic Keratoses
according to Skin Types: A Retrospective Study. Dermatol Pract Concept. 2023;13(4):e2023253. DOI: https://doi.org/10.5826/
dpc.1304a253
Accepted: April 19, 2023; Published: October 2023
Copyright: ©2023 Ammad et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-
NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use,
distribution, and reproduction in any medium, provided the original authors and source are credited.
Funding: None.
Competing Interests: None.
Authorship: All authors have contributed significantly to this publication.
Corresponding Author: Dr. Gaetano Licata, MD, Dermatology Unit, San Antonio Abate Hospital, 80057 Trapani, Italy. Phone:
3276215976; E-mail: gaetano.licata89@gmail.com




  ABSTRACT             Introduction: Seborrheic keratoses (SK), are very common benign skin lesions, which may increase in
                       number and size with age.
                       Objectives: The aim of the study was to assess any differences seen in seborrheic keratoses in relation
                       to different skin types (ST) and lesion location.
                       Methods: This was a retrospective observational study of 10-months period, based on dermoscopic
                       images of seborrheic keratoses and patient history recorded in database. Patients were categorized
                       according to their age, sex, skin type, and location of SK.
                       Results: The frequency of SK remained high on the back for skin type 1, 2, 3 and 4. This same trend
                       was also seen on the face and chest. In skin type 3 we saw a reversal of distribution of SK, the highest
                       frequency remained on the back, and this was followed by the chest rather than the face. In skin type
                       5 and 6, the nature of the distribution of SK was more facial,
                       Conclusions: In summary our study shows that SK are more commonly seen in males than in females,
                       they tend to dominate in sun exposed sites especially the back and the face. Both the smaller and larger
                       sized SK dominated in ST 1 and 2. The lighter to darker shades of color seen in seborrheic keratoses
                       varied in accordance with the skin type, with lighter colored SK being seen more in lighter skin types
                       as compared to darker skin types, whereas bluish colored SK were seen in all skin types except ST 1.


Original Article | Dermatol Pract Concept. 2023;13(4):e2023253                                                                           1
Introduction                                                     St Peters Hospital. We did a retrospective analysis of der-
                                                                 moscopic images of SK in relationship with different patient
Seborrheic keratoses (SK), are common benign skin lesions,       factors, focusing on patient skin type. Location, size (less ore
which increase in number and size with age [1,2]. The di-        more than 6 mm in diameter), pigmentation (dividing the le-
agnosis of SK is usually readily made on clinical and der-       sions into three groups, namely light colored, intermediately
moscopic examination, however at times these lesions may         pigmented lesions and dark pigmented lesions) and prevalent
mimic malignant skin tumors and are excised to exclude           dermoscopic pattern were recorded. There were sixty-four
a malignancy [3]. A better knowledge of clinical and der-        males and fifty-seven females, with ages ranging between
moscopic characteristics of SK may help avoid unnecessary        36-96 years with different Fitzpatrick skin types (ST). A to-
excisions. We recorded the clinical and dermoscopic images       tal of 160 SK in 121 patients were recorded. All characteris-
of a series of SK detected on consecutive patients in an out-    tics are summarized in Table 1 and 2. A wide age range was
patient clinic setting over 10-month period at Ashford and       taken, but there were no patients seen in their twenties or


                                    Table 1. Location of Seborrheric keratoses.
                Location                        ST 1-2 N (%)                     ST 3-4 N (%)                     P value
 Back                                             37 (41.6)                        23 (32.3)                          0.3
 Head and Neck                                        22                               14                             0.5
                                                    (24.7)                           (19.7)
 Chest                                                9                                14                             0.1
                                                    (10.1)                           (19.7)
 Abdomen                                              9                                   4                           0.46
                                                    (10.1)                              (5.6)
 Limbs                                                12                               16                             0.19
                                                    (13.5)                           (22.5)
 Total                                             89 (100)                         71 (100)



                   Table 2. All characteristics: pigmentation, size and prevalent dermoscopic
                                        pattern of Seborrheic keratoses.
             Pigmentation                     ST 1-2 N (%)                 ST 3-4 N (%)                       P value
 Light                                          58 (65.2)                    25 (35.2)                         <0.01
 Intermediate                                   26 (29.2)                     32 (45)                           0.06
 Heavy                                           5 (5.6)                     14 (19.7)                         <0.05
 Size
 <6 mm                                          37 (41.6)                     27 (38)                           0.77
 >6 mm                                          52 (58.4)                     44 (62)                           0.77
 Dermoscopy features
 Milia                                          28 (31.4)                    23 (32.4)                            1
 Comedo like openings                           45 (50.6)                    32 (45.1)                          0.6
 Fat fingers                                    50 (56.1)                    25 (35.2)                         <0.05
 Finger printing                                9 (10.1)                     15 (21.1)                          0.08
 Reticular lines                                 4 (4.5)                      3 (4.2)                             1
 Sharp demarcation                              23 (25.8)                    29 (40.8)                          0.06
 Hypekeratosis                                   6 (6.7)                     12 (16.9)                          0.07
 Looped vessels                                 37 (41.5)                    15 (21.1)                         <0.05
 Total (%)                                      89 (100)                     71 (100)


below. Yeatman et al, wrote about the frequency, nature and      higher number in younger age groups as compared to any
distribution of SKs in 100 Australian adults [4]. Their lowest   previous studies, this was not our experience.
age range was 15-25. Although the frequency of SKs seen             Previous studies have reported the distribution of SKs
in their study showed a rising trend with age, they reported     generally as on the trunk, hence taking chest and back as


2                                                                    Original Article | Dermatol Pract Concept. 2023;13(4):e2023253
        Figure 1. Distribution of Seborrheic keratoses (SKs) according to the skin type. (A-C) Clinical and dermoscopic image of skin
        type 1-2: skin type 1 and 2 showed the high number of SKs which were lightly pigmented. (D-F) Dermoscopic image of skin
        type 3-4: skin type 3 and 4 showed heavy pigmented SKs.




one entity, in our study we have reported that separately. We           types as compared to darker skin types. Commonest local
found the highest numbers were seen on the back, followed               features seen were comedo openings and fat fingers and the
by head/neck, chest and abdomen.                                        least common were reticular lines or network like structures.
    When we compared the distribution of SKs according to               We suggest further studies with higher number in each skin
the skin type, we found a higher percentage of SKs on the               category to be able to further verify these findings.
limbs in skin type 3-4 as compared to lighter skin types, this
difference was not statistically significant. We divided the le-
sion size as a cut off at 6 mm. Our numbers show that larger            References
SK predominated in all skin types.
                                                                         1. Changchien L, Dusza SW, Agero AL, et al. Age- and site-specific
    We also took pigment amount as a category. Lightly                      variation in the dermoscopic patterns of congenital melanocytic
pigmented SKs dominated in our study. Skin type 1 and 2                     nevi: an aid to accurate classification and assessment of mela-
showed the higher number of SKs which were lightly pig-                     nocytic nevi. Arch Dermatol. 2007;143(8):1007-1014. DOI:
mented (Figure 1).                                                          10.1001/archderm.143.8.1007. PMID: 17709659.
                                                                         2. Memon AA, Tomenson JA, Bothwell J, Friedmann PS. Prevalence
    The commonest local features seen in the dermatoscopic
                                                                            of solar damage and actinic keratosis in a Merseyside popula-
images were comedo openings and fat fingers. When com-
                                                                            tion. Br J Dermatol. 2000;142(6):1154-1159. DOI: 10.1046
paring to skin types, fat fingers and looped vessels were a                 /j.1365-2133.2000.03541.x. PMID: 10848739.
common feature in SKs in lighter skin types (< 0.05). Sharply            3. Moscarella E, Brancaccio G, Briatico G, Ronchi A, Piana S,
demarcated borders, finger printing and hyperkeratosis SK                   Argenziano G. Differential Diagnosis and Management on
were more seen in darker skin types, the difference was not                 Seborrheic Keratosis in Elderly Patients. Clin Cosmet Investig
                                                                            Dermatol. 2021;14:395-406. DOI: 10.2147/CCID.S267246.
statistically significant.
                                                                            PMID: 33953590. PMCID: PMC8088980.
    In summary, according to our study, SKs tend to domi-
                                                                         4. Yeatman JM, Kilkenny M, Marks R. The prevalence of sebor-
nate in sun exposed sites especially the back, the lighter to               rhoeic keratoses in an Australian population: does exposure to
darker shades of color varied in accordance with the skin                   sunlight play a part in their frequency? Br J Dermatol. 1997;
type, with lighter colored SK being seen more in lighter skin               137(3):411-414. PMID: 9349339.




Original Article | Dermatol Pract Concept. 2023;13(4):e2023253                                                                           3
