[Current dermatology guidelines in Germany-selected recommendations from 2021 and 2022]. / Aktuelle dermatologische Leitlinien in Deutschland ­ Ausgewählte Empfehlungen aus den Jahren 2021 und 2022.

Guidelines are systematically developed decision-making aids to ensure appropriate clinical care for specific medical conditions. In Germany, dermatological guidelines are developed under the aegis of the German Dermatological Society (DDG) and the Professional Association of German Dermatologists (BVDD), while European and international guidelines are published by organisations such as the European Centre for Guidelines Development (EuroGuiDerm), founded by the European Dermatology Forum (EDF) in cooperation with the Division of Evidence-Based Medicine at Charité-Universitätsmedizin Berlin. In 2021 and 2022, the German guidelines were revised or developed on topics such as the management of anticoagulation during dermatological procedures, chronic pruritus, contact dermatitis, laser therapy of the skin, psoriasis vulgaris, rosacea, extracorporeal photopheresis, onychomycosis, mucous membrane pemphigoid and prevention of skin cancer. A selection of the most important recommendations and innovations in the guidelines is summarized here.

The effectiveness of an extra-curricular lecture for STI prevention and sexual education.

While the incidence of infections with the human immunodeficiency virus largely remained unchanged in Germany, an increase of other sexually transmitted infections (STIs) was observed. The aim was to analyse the effectiveness of our sexual education lecture for students in improving the awareness, knowledge and prevention of STIs. We conducted a cross-sectional survey after students had attended our extra-curricular lecture at the Department of Dermatology of the Ludwig-Maximilians-University of Munich, Germany (LMU). We compared the data with a previously performed study in which the same survey was carried out before the lecture had started. A total of 5866 questionnaires were included in the analysis. After attending the lecture significantly more students were aware of STIs (syphilis: 36.8% (before) vs. 63.5% (after); chlamydia: 30.5% vs. 49.3%; gonorrhoea: 22.4% vs. 38.2%; human papillomaviruses (HPV): 17.7% vs. 30.2%), the transmission pathways of STIs (oral: 36.6% vs. 82.6%; vaginal: 81.8% vs. 97.3%; anal: 42.8% vs. 94.0%; penile: 68.7% vs. 92.1%), knew that the HPV vaccination is directed against a virus (36.8% vs. 56.9%) and were interested in receiving a vaccination (57.7% vs. 78.8%). This study demonstrates the positive educative effects of our lecture for awareness and improved knowledge of STIs. To satisfy the need for a comprehensive sexual education, a combination of school and health facility-based programmes should be implemented as one single lecture cannot convey the entire information about STIs.

First ex vivo cultivation of human Demodex mites and evaluation of different drugs on mite proliferation.

BACKGROUND: Demodex spp. mites are the most complex resident of the human skin microbiome. Although they are considered commensals, they can be pathophysiologically relevant in inflammatory skin diseases like rosacea. Until now, there is no culture system available for these mites except for using live vertebrate hosts. OBJECTIVES: Our aim was to establish an ex vivo culture of human Demodex mites and to characterize the sebogenesis-dependent mite density. METHODS: Demodex mites were cultivated in pilosebaceous units of human skin explants, called human organotypic skin explant culture (hOSEC). Furthermore, different sebogenesis-modifying additives were evaluated. Mites and mite survival were evaluated using light and fluorescence microscopy. RESULTS: After 90 days of incubation, living Demodex mites - including eggs, larvae and nymphs - were detected in the dissected skin samples. Incubation for 30 days with anabolic steroids (testosterone and trenbolone) as well as retinol and retinoic acid (isotretinoin) yielded a reduced mite density. CONCLUSIONS: With this technique, mites can be cultivated ex vivo for the first time, thereby establishing new ways to investigate Demodex spp. The sebostatic effect of isotretinoin might explain the mechanism of action in the off-label treatment of rosacea. We anticipate our findings to be the basis of an accelerated research on our most complex commensal, its life, biology and physiology.

Retrospective analysis of alpha-human papillomavirus (HPV) types in tissue samples from anogenital dysplasias - introduction of the RICH (Risk of HPV-related Carcinoma in HIV+/- patients) score.

BACKGROUND: Chronic viral infections caused by highly contagious human papillomaviruses (HPVs) from the alpha genus are a substantial risk factor for tumour diseases. OBJECTIVES: The goal of this study was to compare the HPV infection pattern with histology in a patient group of immunocompromised HIV+ and non-immunocompromised patients with anal intraepithelial neoplasia. MATERIALS AND METHODS: Tissue samples (n = 210) from the anogenital area of 121 patients underwent retrospective histological and molecular examination for HPV DNA prevalence by chip analysis. The study was part of a cancer screening from the Dermatology Department of the LMU Munich, Germany. All data were collected and processed anonymously. RESULTS: HPV 6 or 11 are more abundant in tissue samples from histologically diagnosed condylomata acuminata (47.7%) compared to grade 1, 2, and 3 intraepithelial neoplasias (IN 1-3). Detection of high-risk (hr) alpha-HPV DNA was significantly higher in tissue samples from IN 3 (67.5%) compared to IN 1 and 2 (12.9%), and compared to condylomata acuminata (29.5%). No HPV types were detected in histologically unremarkable tissue samples. There was a significant association between the prevalence of HPV 16 and the classifications IN 1 to IN 3 (χ2 (2) = 13.62, P = 0.001). We identified a significant correlation between the prevalence of high-risk and low-risk (lr) HPV types and HIV, especially mixed infections of different HPV types correlated with high-grade IN. Based on the present data, we suggest the risk of carcinoma in HIV+/- patients (RICH) score and test it in the 121 patients. CONCLUSIONS: hr alpha-HPVs, mainly HPV 16, are associated with increased oncogenic potential of premalignant lesions (IN 1-3), especially in HIV+ patients. Based on the combination of HIV/HPV-testing and histological analysis, we identified correlations that could potentially forecast the risk of malignant transformation and summarized them in the form of RICH score.

Corynebacterium kroppenstedtii subsp. demodicis is the endobacterium of Demodex folliculorum.

BACKGROUND: Demodex spp. mites are the most complex member of the human skin microbiome. Mostly they are commensals, although their pathophysiological role in inflammatory dermatoses is recognized. Demodex mites cannot be cultivated in vitro, so only little is known about their life cycle, biology and physiology. Different bacterial species have been suggested to be the endobacterium of Demodex mites, including Bacillus oleronius, B. simplex, B. cereus and B. pumilus. OBJECTIVES: Our aim was to find the true endobacterium of human Demodex mites. METHODS: The distinct genetic and phenotypic differences and similarities between the type strain and native isolates are described by DNA sequencing, PCR, MALDI-TOF, DNA-DNA hybridization, fatty and mycolic acid analyses, and antibiotic resistance testing. RESULTS: We report the true endobacterium of Demodex folliculorum, independent of the sampling source of mites or life stage: Corynebacterium kroppenstedtii subsp. demodicis. CONCLUSIONS: We anticipate our finding to be a starting point for more in-depth understanding of the tripartite microbe-host interaction between Demodex mites, its bacterial endosymbiont and the human host.

Distribution of high-risk α-genus human papillomavirus genotypes impacts cutaneous neoplasms.

BACKGROUND: High-risk α-genus human papillomaviruses (α-HPVs) are linked to cervical and genital carcinomas; however, their correlation with cutaneous squamous cell carcinoma (cuSCC) or premalignant skin lesions remains controversial. OBJECTIVE: We evaluated the contribution of high-risk α-HPV to the occurrence of cuSCC, Bowen's disease and actinic keratosis (AK), and the distribution of high-risk α-HPV genotypes in these cutaneous tumours. METHODS: HPV genotypes were determined using a commercial PCR-based microarray on skin tissue samples collected from 76 [38 young (<60 years) and 38 elderly (>60 years)] cuSCC, 34 Bowen's disease, 48 AK patients and 10 young controls. Associations between α-HPV prevalence and relevant risk factors were analysed. RESULTS: High-risk α-HPV was more frequently detected in cuSCC patients (57.9%) than in the patients with Bowen's disease (38.2%), AK (0.0%) and control patients (10.0%). The high-risk α-HPV prevalence was higher in young than in elderly cuSCC patients (65.8% vs. 50.0%, P = 0.031). The most common HPV type was 16, present in 90.9% of all HPV-carrying cuSCC patients. Multiple infections with different high-risk α-HPV types were found in 20.5% of HPV-related cuSCC, whereas only single infection with type 16 was found in Bowen's disease. Although sun exposure is known as a major risk factor for cuSCC, high-risk α-HPVs were more frequently found in non-exposed sites rather than in sun-exposed sites of cuSCC. CONCLUSION: Multiple infections, as well as single infection with high-risk α-HPV may link to cuSCC. In spite of the involvement of high-risk α-HPV at high levels in cuSCC and Bowen's disease, no high-risk α-HPV was detected in AK patients, suggesting that Bowen's disease rather than AK might be involved in the development of HPV-related cuSCC as a precursor.

Efficient isolation and observation of the most complex human commensal, Demodex spp.

Demodex spp. mites are an often neglected member of the human skin microbiome. Mostly they are commensals, although their pathophysiological role in rosacea, spinulosis folliculorum, and other skin diseases is recognized. Little is known about their life cycle, biology, and physiology. Demodex mites cannot be cultivated in vitro, thereby complicating research immensely. The manual extraction from human sebum is laborious and death can only be detected by surrogate markers like ceased movement or loss of fluorescence. Here we present a new approach for the extraction of larger mite numbers and the hitherto most precise way to detect death. The extraction of mites from sebum and debris by hand can be accelerated by a factor 10 using sucrose gradient centrifugation, which is well tolerated by the mites. Staining with propidium iodide allows for easy identification of dead mites, excluding frail mites that stopped moving, and has no negative effect on overall mite survival. We anticipate our methods to be a starting point for more sophisticated research and ultimately in vitro cultivation of Demodex spp. mites.