Fordyce spots (FS) are heterotopic sebaceous glands affecting mostly oral and genital mucosa, commonly misdiagnosed with sexually transmitted infections. In a single-center retrospective study, we aimed to assess the ultraviolet-induced fluorescencedermatoscopy (UVFD) clues of Fordyce spots and their common clinical simulants: molluscum contagiosum, penile pearly papules, human papillomavirus warts, genital lichen planus, and genital porokeratosis. Analyzed documentation included patients’ medical records (1 September–30 October 2022) and photodocumentation, which included clinical images as well as polarized, non-polarized, and UVFD images. Twelve FS patients were included in the study group and fourteen patients in the control group. A novel and seemingly specific UVFD pattern of FS was described: regularly distributed bright dots over yellowish-greenish clods. Even though, in the majority of instances, the diagnosis of FS does not require more than naked eye examination, UVFD is a fast, easy-to-apply, and low-cost modality that can further increase the diagnostic confidence and rule out selected infectious and non-infectious differential diagnoses if added to conventional dermatoscopic diagnosis.

Porokeratosis is a heterogeneous group of keratinising disorders characterised by the presence of particular microscopic structural changes, namely the presence of the cornoid lamella. This structure develops as a consequence of a defective isoprenoid pathway, critical for cholesterol synthesis. Commonly recognised variants include disseminated superficial actinic porokeratosis, disseminated superficial porokeratosis, porokeratosis of Mibelli, palmoplantar porokeratosis (including porokeratosis palmaris et plantaris disseminata and punctate porokeratosis), linear porokeratosis, verrucous porokeratosis (also known as genitogluteal porokeratosis), follicular porokeratosis and porokeratoma. Apart from the clinical presentation and epidemiology of each variant listed, this review aims at providing up-to-date information on the precise genetic background, introduces imaging methods facilitating the diagnosis (conventional and ultraviolet-induced fluorescence dermatoscopy, reflectance confocal microscopy and pathology), discusses their oncogenic potential and reviews the literature data on the efficacy of the treatment used, including the drugs directly targeting the isoprenoid–mevalonate pathway.

Citation: Al-Nasiri M, Navarrete-Dechent C, Korecka K, Salwowska N, Goldust M, Pietkiewicz P. Ultraviolet Reflectance Dermatoscopy of Trichobacteriosis Axillaris Reveals Peripilar Yellow-Green Luminescent Concretions. Dermatol Pract Concept. 2023;13(2):e2023169. DOI: https://doi.org/10.5826/dpc.1302a169 Accepted: February 4, 2023; Published: April 2023 Copyright: ©2023 Al-Nasiri 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 Email: pietkiewicz.pp@gmail.com Keywords : dermatoscopy, imaging, ultraviolet radiation, trichomycosis, corynebacteria This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Melanonychia striata longitudinalis might involve one or more fingers and/or toes and might result from several different causes, including benign and malignant tumors, trauma, infections, and acti-vation of melanocytes that might be reactive or related to the pigmentary trait,drugs and some rare syndromes.This broad differential diagnosis renders the clinical assessment of melanonychia striata particularly challenging. Nail matrix melanoma is relatively rare, occurs almost always in adults in-volves more frequently the first toe or thumb.The most common nail unit cancer,squamous cell carcinoma / Bowen disease (SCC) of the nail matrix is seldom pigmented. Histopathologic examina-tion remains the gold standard for melanoma and SCC diagnosis,but excisional or partial biopsies from the nail matrix require training and is not routinely performed by the majority of clinicians.Furthermore, the histopathologic evaluation of melanocytic lesions of the nail matrix is particularly challenging, since early melanoma has only bland histopathologic alterations. Dermatoscopy of the nail plate and its free edge significantly improves the clinical diagnosis, since specific patterns have been associated to each one of the causes of melanonychia. Based on knowledge generated and pub-lished in the last decades, we propose herein a stepwise diagnostic approach for melanonychia striata longitudinalis: 1) Hemorrhage first 2) Age matters 3) Number of nails matters 4) Free edge matters 5) Brown or gray? 6) Size matters 7) Regular or irregular and, finally,“follow back”.

Actinic keratoses (AK) are one of the most frequent reasons for consultations in dermatology. Ultraviolet-induced fluorescence dermatoscopy (UVFD) is a new method that allows the assessment of lesions in a spectrum of light that originates from the fluorochromes emitting UV-excited luminescence. The aim of this study was to assess the UVFD features of AKs before PDT and their intensity in field cancerization and single lesions. This retrospective study was conducted from June to November 2023. Lesions were assessed with the Olsen scale clinically and dermatoscopically (DermLite DL5, 10x magnification) and photographed. UVFD fluorescence was categorized as 'none', 'weak', 'moderate', and 'intense'. A 1-mm thick layer of 10% 5-ALA gel was applied to single lesions or cancerization field (depending on the patient) and covered with an occlusive dressing for 3 hours. Prior the application of 10% 5-ALA gel, the lesions were degreased with an alcoholic solution. The occlusion was removed, and the field was cleaned with a 0,9% saline solution. Afterward, each lesion was photographed in polarized light and UVFD mode. A total of 194 dermatoscopic images were analyzed, 111 corresponded to field cancerization and 81 to single AKs. Overall, weak fluorescence was noticed in 22 of them (11,3%), moderate in 107 (55,15%), and intense in 65 (33,5%). Amongst field cancerization (111 images), weak fluorescence was seen in 11 (9.9%), moderate in 68 (61,26%), and intense in 32 (28,82%). In single lesions (81 images), weak fluorescence was detected in 11 (13,2%), moderate in 39 (46,99%), and intense in 33 (28.83%) of the lesions. Slightly more intense fluorescence was noticed in higher Olsen grade (p=0.04). UVFD can enhance our efficacy of pre-procedural examination and might arise as a useful device to predict the therapeutic effect of PDT.

Objectives: Actinic keratoses (AKs) are one of the most common reasons for consultation in the elderly population. This study aimed to assess the efficacy of 5-ALA PDT in AK treatment using high-frequency ultrasonography (HFUS) to evaluate skin layer changes during therapy. Methods: In our study, we included 44 AK patients aged 53 to 89 years. All patients had lesions clinically evaluated with the Olsen and AKASI scale. HFUS imaging was performed on seemingly healthy skin and lesions before and at 4, 8, and 12 weeks of therapy. Ultrasound markers such as skin thickness, echogenicity, and pixel intensity were measured. 5-ALA was applied under occlusion for 3 h. After removing the occlusive dressing, 5-ALA was removed with a saline solution and a directed therapy with a BF-200 lamp. Full follow-ups of 56 markers of suitable quality were selected. Results: The thickness of SLEB significantly decreased in the following weeks compared to the pre-therapy results, reaching its lowest values after 12 weeks. The average pixel intensity significantly increased in each skin layer after therapy (p < 0.01). For SLEB, there were statistically significant differences in LEP, MEP and contrast. The AKASI score before and after treatment was determined for the 39 patients who underwent follow-up at week 12. The median AKASI score was 3.2 (1.2–8.6) before treatment and 0.6 (0–2.8) after. Conclusions: According to the literature data, this is the first study describing the ALA-PDT treatment efficacy in different AK severities evaluated in HFUS. HFUS provides a valuable non-invasive tool for monitoring the efficacy of PDT in AK treatment, showing significant improvements in skin texture and structure.