10.5826/dpc.1303a242
text/xml
2160-9381
3243
en
Enzo Errichetti
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
fluorescence
Ultraviolet-Induced Fluorescence Dermoscopy Reveals Fluorescent Clues in Pitted Keratolysis
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Research Letter
2023-07-31
2023-02-18
2023-07-31
2023-08-24
e2023242
Dermatol Pract Concept
Enzo Errichetti
2023/07/31
10.5826/dpc.1303a242
e2023242
Institute of Dermatology, Santa Maria della Misericordia University Hospital, Udine, Italy
2160-9381
fluorescence
en
e2023242
Yasuma A, Ochiai T, Azuma M, et al.. Exogenous coproporphyrin III production by Corynebacterium aurimucosum and Microbacterium oxydans in erythrasma lesions. J Med Microbiol. 2011;60(Pt 7):1038-1042. doi: 10.1099/jmm.0.027276-0. PMID: 21393451.
Ultraviolet-Induced Fluorescence Dermoscopy Reveals Fluorescent Clues in Pitted Keratolysis
https://dpcj.org/index.php/dpc/article/download/3243/2212
     Ultraviolet-Induced Fluorescence Dermatoscopy
     Reveals Fluorescent Clues in Pitted Keratolysis
              Paweł Pietkiewicz1,2, Cristian Navarrete-Dechent3,4, Natalia Salwowska2,5,
                      Carmen Cantisani6, Mohamad Goldust7, Enzo Errichetti8


1 Dermatology Private Practice, Poznań, Poland
2 Polish Dermatoscopy Group, Poznań, Poland
3 Department of Dermatology, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
4 Melanoma and Skin Cancer Unit, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
5 Department of Dermatology, School of Medicine, Medical University of Silesia, Katowice, Poland
6 Dermatology Unit, Department of Clinical Internal Anesthesiologic Cardiovascular Sciences, “Sapienza Medical School”
   University of Rome, Rome, Italy
7 Department of Dermatology, Yale School of Medicine, Yale University, New Haven, Connecticut, USA
8 Institute of Dermatology, Santa Maria della Misericordia University Hospital, Udine, Italy



Key words: ultraviolet radiation, dermoscopy, pitted keratolysis, corynebacterium, fluorescence
Citation: Pietkiewicz P, Navarrete-Dechent C, Salwowska N, Cantisani C, Goldust M, Errichetti E. Ultraviolet-Induced Fluorescence
Dermatoscopy Reveals Fluorescent Clues in Pitted Keratolysis. Dermatol Pract Concept. 2023;13(3):e2023242.
DOI: https://doi.org/10.5826/dpc.1303a242
Accepted: April 12, 2023; Published: July 2023
Copyright: ©2023 Pietkiewicz 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: Paweł Pietkiewicz, Centrum Medyczne Zwierzyniecka, Zwierzyniecka Street 30/28, Poznań 60-814.
Telephone: +48 602 133 503 E-mail: pietkiewicz.pp@gmail.com




Introduction                                                             clinically similar conditions, mainly including viral warts
                                                                         and tinea pedis, may sometimes be troublesome. In such
Pitted keratolysis (PK) is a corynebacterial infection of the            cases, recognition of PK may be assisted by dermatoscopy
soles manifesting as multiple plantar pits caused by desmo-              (multiple crateriform indentations of the soles), Wood lamp
somal alteration in the stratum corneum due to enzymatic                 examination (coral red fluorescence of the pits), direct mi-
activity of P1 and P2 bacterial serine proteases [1]. Predis-            croscopy, and culture.
posing factors include hyperhidrosis, occlusion, and reduced
acidity of the skin surface [1].
                                                                         Case Presentation
    Apart from the pits, patients may report burning sensa-
tion and malodour. In some instances, PK may be accompa-                 A 49-year-old male presented to the dermatology outpatient
nied with other corynebacterial infections such as erythrasma            clinic due to genital lichen sclerosus. During the skin check,
and/or trichobacteriosis axillaris [2]. Although the diagnosis           multiple plantar and interdigital pits were noted and further
is mostly based on clinical presentation, differentiation from           confirmed with dermatoscopy (Figure 1). Ultraviolet-induced



Research Letter | Dermatol Pract Concept. 2023;13(3):e2023242                                                                         1
Figure 1. Pitted keratolysis in a 49-year-old patient. (A) Clinical presentation showing crateriform plantar pits (black arrowheads).
(B) ­Examination with Wood lamp displays coral-red excited fluorescence of the pits (black arrowheads) and polycyclic figures (white
­arrowheads). (C) Dermatoscopy of toe web space displays small pits with a free edge of the peripheral scale that coalesce into larger areas
 (black arrowheads). (D) Ultraviolet-induced fluorescence dermatoscopy of toe web space reveals excited fluorescence - coral-red eccrine dots
 (white frames; magnified view in the box) and perieccrine clods (black arrowheads) corresponding to crateriform pits. (E) Dermatoscopy of
 the sole shows sparse plantar pits with a free edge of peripheral scale (black arrowheads) and irregular scaling, seen mainly in the furrows
 (white arrowheads). (F) Ultraviolet-induced fluorescence dermatoscopy of the sole reveals excited fluorescence - pale coral-red pits with a
 free edge of scale (black arrowheads) and pale coral-red parallel ridge pattern, as well as pale coral-red clods in the ridges (white arrows)
 (DL5, Dermlite,×10 magnification).



2                                                                            Research Letter | Dermatol Pract Concept. 2023;13(3):e2023242
fluorescence   dermatoscopy      (UVFD;      peak   wavelength      producing coproporphyrin III [5]. We hypothesize that
365nm, DL5, Dermlite) displayed multiple pits surrounded            the infection might begin within the acrosyringium as a
with coral-red scale, coral-red parallel ridge pattern (PRP)        coral-red eccrine dots and clods that precede the develop-
(absent in visible light), and coral-red eccrine dots and clods.    ment of coral-red PRP and finally develop into coral-red
                                                                    crateriform pits. The presence of the PRP pattern in mis-

Conclusions                                                         cellaneous dermatoses was summarized in Table 1. The
                                                                    specificity of our findings requires further confirmation
UVFD is a novel diagnostic technique implementing UV                in larger series of cases. In our opinion, these newly re-
radiation to produce fluorescent images based on Stokes             ported UVFD clues might be helpful to promptly differen-
shift phenomenon [3,4]. Coral-red excited emission spec-            tiate PK from its common clinical and/or dermatoscopic
trum is likely caused by the presence of Corynebacteria             mimickers.




                   Table 1. Differential diagnosis of parallel ridge pattern on dermatoscopy.
           Diagnosis                                            Clues                                        Clinical Pearl
 Acral lentiginous melanoma         Usually other clues to melanoma; chaotic distribution
                                    of structures, colours (patchy pigmentation) or border
                                    abruptness; accentuated perieccrine pigmented circles,
                                    obliterated eccrine duct openings; solitary standing-out
                                    lesion (‘a priest in the snow’); large size (>7mm)
 Acral compound or                  Usually long history or congenital character; concentric
 combined nevus                     architecture and/or elevation
 Exogenous pigmentation             Different shades depending on pigment colour                    In many instances can be
 (e.g. dirt, hair dye, henna,                                                                       removed with alcohol pad
 silver nitrite, potassium
 permanganate, etc.)
 Ethnic pigmentation                No other melanoma features; harmonious in regard to
                                    structure and colour distribution; multiple
 Laugier-Hunziker syndrome /        No other melanoma features; harmonious in regard to
 Peutz-Jeghers syndrome             structure and colour distribution; multiple; possibly
                                    accompanied by longitudinal melanonychia and/or
                                    mucosal melanotic macules
 Acral angioma                      Presence of red dots on the ridge; organized
 Subcorneal hemorrhage              Often well-defined, ‘cracked’ appearance, orange, reddish-      Can be removed with scalpel
                                    to-black colour
 Acral pigmented viral wart         Patchy pigmentation resembling acral lentiginous
                                    melanoma, yet no other melanoma features
 Pitted keratolysis                 Multiple crateriform pits with a free edge of scale;            Parallel ridge pattern can be
                                    common history of plantar hyperhidrosis                         visualized with ultraviolet-
                                                                                                    induced fluorescence
                                                                                                    dermatoscopy only
 Tinea nigra                        Short history: brown to gray pigmentation arranged in
                                    thin bundles of short lines (‘spicules’) forming reticulate
                                    pattern, but also parallel ridge pattern especially at the
                                    lesion’s periphery; no parallel furrow pattern




References                                                           2. Al-Nasiri M, Navarrete-Dechent C, Korecka K, Salwowska N,
                                                                        Goldust M, Pietkiewicz P. Ultraviolet-Induced Fluorescence
 1. Hermanns-Lê T, Garcia R, Arrese JE, Piérard GE. Pitted              Dermatoscopy of Trichobacteriosis Axillaris Reveals P
                                                                                                                            ­ eripilar
    Keratolysis: New Ultrastructural Insight in Keratohyalin
    ­                                                                   Yellow-Green Luminescent Concretions. Dermatol Pract Con-
    Granule and Corneodesmosome Alterations. Exog Dermatol.             cept. 2023;13(2):e2023169. DOI: 10.5826/dpc.1302a169.
    2004;3:107-111. DOI: 10.1159/000086942.                             PMID: 36795854. PMCID: PMC10188146.



Research Letter | Dermatol Pract Concept. 2023;13(3):e2023242                                                                       3
3. Pietkiewicz P, Navarrete-Dechent C, Mayisoğlu H, Jolly G,       2023;13(2):e2023135. DOI: 10.5826/dpc.1302a135. PMID:
   Kutlu Ö, Errichetti E. Pink-Red Fluorescence Observed in        36795853. PMCID: PMC10188151.
   Ultraviolet-Induced Fluorescence Dermoscopy of Psoriatic
   ­                                                            5. Yasuma A, Ochiai T, Azuma M, et al. Exogenous c­ oproporphyrin
   Plaques. Dermatol Pract Concept. 2023;13(3):e2023243. DOI:      III production by Corynebacterium aurimucosum and Micro-
   10.5826/dpc.1303a243.                                           bacterium oxydans in erythrasma lesions. J Med M     ­ icrobiol.
4. Pietkiewicz P, Navarrete-Dechent C. Scabies Mite is Bright      2011;60(Pt 7):1038-1042. DOI: 10.1099/jmm.0.027276-0.
   Green Under UV Dermatoscopy. Dermatol Pract Concept.            PMID: 21393451.




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