Experimental Dermatology

A phase 2, randomised, double-blind, placebo controlled trial has been conducted in mild to moderate patchy alopecia areata (AA). This demonstrated significant and dose related improvements in hair regrowth with STS01, a controlled release, topical formulation of dithranol. Here we report the results of the Alopecia Areata Symptom Impact Scale (AASIS) that assesses the severity of symptoms, daily functioning and feelings. Similar to trials in severe AA, significant improvements in hair regrowth did not translate into significant health-related quality of life (HRQoL) improvements, even in patients with complete hair regrowth, although there was some treatment-related correlation between changes in AASIS scores from baseline and clinical assessment SALT scores. The use of current HRQoL methods or indeed new measures in development for future trials, will have considerable challenges: patients may not have a true baseline at entry, may develop coping mechanisms, and there may be a delay between physical and psychological improvement.

Vitiligo is an acquired pigmentary disorder of the skin and mucus membranes. Previous study has demonstrated that autologous cultured epithelial grafts (ACEG) is an effective treatment for stable vitiligo. However, extraction of full-thickness skin might result in scar formation at donor site, which have hindered the wider application of this technology, especially for patients requiring large-area transplantation. Hair follicle as a source of keratinocyte and melanocyte, could be potential source of cells for preparation of autologous cultured sheet. Through culture system optimization, we have demonstrated maintenance of undifferentiated hair follicle-derived cells in feeder-independent culture system. After expansion, the hair follicle cells were directed to differentiate into a multi-layered, epidermis-like sheet. Cell identity, viability, purity, genomic stability, and antiseptic testing for hair follicle-derived epithelial sheet (HFES) were evaluated to ensure its safety. Immunofluorescence staining showed that basal keratinocytes were the main cell type of the autologous HFES. Optimization of culture conditions leads to increased melanocyte proliferation and functionality. Transcriptomic analysis confirmed upregulation of melanosome maturation genes. The proportions of cells are also similar to composition of cells under physiological conditions. Transplantation of HFES to depigmented areas in patients with stable vitiligo results in skin repigmentation. This technology provides a novel therapeutic option for vitiligo management.

Background In clinical trials for alopecia areata (AA) the treatment effect (percentage of hair loss) is estimated using the Severity of Alopecia Tool (SALT) score. Trials in patients with severe AA (>=50% hair loss) employed a local rating of the SALT score performed at trial sites by different investigators. However, in mild-to-moderate AA (<= 50% hair loss) where SALT scores are lower, potential inter rater variability and margin of error may compromise the results. Objectives To compare Centralised and Local measurement of hair loss in mild moderate AA. Methods In a Phase 2 clinical trial a centralised measurement of hair loss was performed from photographic images taken using a standardised protocol and professional camera equipment. Local scoring was also undertaken at screening/baseline for eligibility. We assessed: the repeatability of the central system (screening vs baseline values), the reproducibility of the central versus the local rating system and the potential impact of each method on the endpoints using a Monte-Carlo simulation method. Results There was good agreement and consistency of scoring with Central rating. This provided much smaller margins of error, 50% lower than Local rating. The simulations demonstrated that substituting Local rating for Central rating would result in a reduction of the likelihood of a statistically significant outcome by at least 50% depending on the SALT score defined clinical response endpoint. Conclusions Central rating is most appropriate in the Phase 2 learning stage of clinical development and provides an accurate representation of the quantity of hair loss, minimising error and ensuring consistency in measurements.

BackgroundPsoriasis is a chronic immune-mediated inflammatory disease (IMID) with systemic involvement. In mild-to-moderate disease, circulating cytokines may inadequately capture systemic inflammatory burden. Composite haematological indices derived from complete blood counts, such as the systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI), have emerged as sensitive prognostic markers of systemic inflammation, including in psoriasis. This exploratory post hoc analysis investigated the effects of orally administered herring roe oil (HRO), a phospholipid-rich marine oil, on systemic inflammation in patients with mild-to-moderate psoriasis utilizing these biomarkers. MethodsData were analysed from a randomized, double-blind, placebo-controlled 26-week clinical study which investigated HRO supplementation in patients (N = 64) with mild-to-moderate psoriasis (NCT03359577). SII, SIRI, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) were calculated at baseline, week 12, and week 26 for patients where baseline complete blood counts (CBCs) were available (n = 60). Patients missing baseline CBCs were excluded from the analysis. Continuous changes were assessed using ANCOVA with baseline adjustment. Categorical responder analyses were performed with 25% and 30% reduction thresholds and stratification by baseline biomarker medians were performed to evaluate treatment responses and impact of baseline inflammation. ResultsCompared with placebo, HRO treatment resulted in significant mean reductions in SII, SIRI, and PLR at week 26, with supportive trends and responder effects observed as early as week 12 compared to placebo. Patients with elevated baseline inflammatory indices showed the greatest reductions in systemic inflammation. Stratification by baseline SII further revealed enhanced clinical benefit, with statistically significant PASI50 response rates in the HRO arm at week 26 among patients with lower baseline SII. ConclusionHRO supplementation was associated with a time{square}dependent reduction in systemic inflammatory biomarkers in mild{square}to{square}moderate psoriasis patients. These findings support the utility of composite inflammatory indices for monitoring systemic inflammation and suggest that baseline SII may have utility in predicting treatment response and may be a useful tool for stratification in clinical trials in mild to moderate psoriasis patients. These results could also suggest platform-potential of HRO for resolution{square}oriented interventions across several inflammatory conditions.

Background There are no licensed treatments for patients with mild to moderate patchy alopecia areata (AA). Objectives To evaluate the efficacy, safety and dose response of STS01, a novel nanoparticle controlled release, topical formulation of dithranol/Prosilic. Methods In a phase 2, double blind study, adult patients with mild to moderate AA (guideline 10% to 50% of scalp hair loss) were randomly assigned to STS01 at doses of 0.25%, 0.5%, 1%, 2% or placebo, daily for 6 months. The primary endpoints included the proportion of patients achieving a >=30% improvement in Severity of Alopecia Tool (SALT) score, and percentage change from baseline in SALT score. This minimum level of improvement is generally accepted as an indicator of the population likely to progress to complete regrowth Results A total of 155 patients were randomized and treated (placebo, n=32; STS01 groups, n=30 to 31). STS01 1% met the primary efficacy endpoint of >=30% SALT score improvement compared to placebo: 75.9% (95% CI, 60.3 to 91.4%) vs 36.7% (95% CI, 19.4 to 53.9%) at 6 months; p=0.0037. The least squares (LS) mean percentage change in SALT score from baseline to end of treatment showed a clear dose response relationship; STS01 0.5% was the minimally effective dose and 2% the maximum tolerated dose, and there was a statistically significant improvement in the STS01 1% group (minus 55.0% vs +0.6% with placebo; p<0.01). Significant improvements (p<0.05) in LS mean percentage changes from baseline in SALT scores were demonstrated in the STS01 1% group at 2 months (-28.6% vs 12.8%), 4 months (-57.2% vs 1.5%), and 6 months (minus 67.0% vs 0.6%). Clinical Global Impression improvement was reported in 72.0% of patients with STS01 1% vs 41.7% with placebo (p<0.05). The most commonly reported treatment emergent adverse events were skin irritation reactions, but were mostly mild (STS01: 56.7% to 71.0%; placebo: 21.9%) or moderate (STS01:13.3% to 35.5%; placebo: 0%) and manageable by reduced frequency of application. There were 15 skin-related discontinuations with STS01 (12.2%) and 2 (6.3%) with placebo. Conclusions STS01 demonstrated a clear dose response, with STS01 1% dose optimally more effective than placebo for hair regrowth with minimal tolerance concerns in mild to moderate patchy AA. Skin irritation reactions were generally manageable and there were no new safety signals. Further characterisation of the STS01 1% dose is planned in a phase 3 study. Chief Investigator AGM reports fees from Soterios Ltd. Chief Statistician DMF is an employee of Soterios Ltd. All other authors were Principal Investigators in the trial and their clinics were reimbursed for the work involved. Most also had sponsorship in the form of consultancies, investigational roles or lecturing roles on behalf of other Dermatological pharmaceutical companies

BackgroundClinical and genetic evidence on the association between atopic dermatitis (AD) and subsequent psoriasis remains conflicting, and it is unclear whether this risk is modified by systemic treatments. Recent reports suggest type 2-targeted biologics may unmask psoriasis in AD patients, but data are limited. We thus aimed to assess whether AD is associated with incident psoriasis and whether this risk differs by systemic treatment, particularly biologics versus conventional systemic immunosuppressants (cvIS). MethodsScoping analyses informed a locked analytic design, preregistration at OSF, and confirmatory execution. Propensity score-matched analyses compared AD with non-AD controls and biologics with cvIS. Sensitivity analyses, Cox model triangulation, and control outcomes assessed robustness. FindingsAmong [~]300,000 matched pairs, AD was associated with increased psoriasis risk (primary HR 3.81, 95% CI 3.35-4.34), consistent across all 8 sensitivity analyses and model triangulation. Biologic treatment was associated with reduced psoriasis risk versus cvIS (primary HR 0.20, 95% CI 0.11-0.35), consistent across 6 of 7 evaluable sensitivity analyses and Cox triangulation. Positive and negative control outcomes showed expected directional patterns. InterpretationAcknowledging limitations including residual confounding and coding misclassification, AD was associated with increased psoriasis risk and biologics with lower psoriasis risk than cvIS. FundingDFG (EXC2167, SFB1526, LU877/25-1), Schleswig-Holstein Excellence-Chair Program, Swedish Society for Dermatology and Venereology, and the Tore Nilson Foundation. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSAtopic dermatitis (eczema) and psoriasis are the two most common chronic inflammatory skin diseases worldwide. For a long time, doctors and researchers assumed these two conditions could not occur in the same person, as they were thought to involve opposing immune responses. However, this view has been challenged over the past decade. Some large studies, including population-based cohorts from Taiwan and the United Kingdom, have found that people with eczema may be at higher risk of developing psoriasis over time, while other studies, including genetic analyses, have suggested the opposite: that the two diseases may actually protect against each other. This conflicting picture has left clinicians uncertain about the true relationship between the two diseases in everyday clinical practice. A separate but related concern has emerged with the introduction of a new class of highly effective treatments for eczema, biologics, particularly dupilumab. Case reports and observational studies, including a large study published in JAMA Dermatology in 2025, have raised the possibility that these medications might trigger psoriasis in some patients, potentially by shifting the immune system from one inflammatory pattern to another. However, prior studies on this question had important methodological limitations: they were not pre-planned and registered before data collection, they did not always tightly link treatment use to an eczema diagnosis, and critically, none compared biologic treatment directly against conventional immunosuppressant medications, the most relevant clinical comparator. Added value of this studyThis study is a large and methodologically rigorous investigation of both questions: whether eczema itself increases the risk of developing psoriasis, and whether the type of systemic treatment used for eczema influences that risk. Using a database of over 110 million electronic health records from across the United States, we matched approximately 300,000 patients with eczema to 300,000 patients without eczema and followed them for up to seven years. We also compared nearly 5,500 patients treated with biologics to an equal number treated with conventional immunosuppressants. Crucially, our study was pre-registered before any data were analyzed, meaning the research questions, methods, and analyses were locked in advance and could not be adjusted based on what the data showed. We also used a range of additional analyses to test whether our findings were robust, including checks using outcomes that should not be affected by eczema or its treatment (such as appendectomy and hearing loss), which confirmed that our results were not likely explained by bias alone. We found that eczema was associated with an increased risk of developing psoriasis, but that this risk was substantially influenced by the choice of comparison group, ranging from approximately 1.4-fold to nearly 4-fold depending on the analytical approach. More strikingly, we found that patients treated with biologics had a markedly lower risk of developing psoriasis compared with those treated with conventional immunosuppressants, the opposite of what prior reports had suggested. This finding was consistent across nearly all additional analyses performed. Implications of all the available evidenceTaken together with existing evidence, these findings suggest two important conclusions. First, clinicians should be aware that eczema, particularly moderate-to-severe eczema requiring systemic treatment, may carry an elevated risk of developing psoriasis over time. This does not mean that all patients with eczema need to be screened for psoriasis routinely, but it does support clinical awareness and monitoring in higher-risk patients. Second, and perhaps most importantly for treatment decisions, biologics do not appear to increase the risk of psoriasis compared with conventional immunosuppressants and may in fact be associated with a lower risk. This provides reassurance for patients and clinicians considering biologic therapy and challenges the narrative that these medications trigger psoriasis. Future research should aim to confirm these findings in other populations, investigate the biological mechanisms underlying the relationship between eczema and psoriasis, and examine whether specific biologic agents differ from one another in their effects on psoriasis risk.

PurposeUnderstanding patient perspectives is essential to improving quality and satisfaction of care in dermatology clinics. In Saudi Arabia, limited national data exist on patients educational needs and communication barriers. This study aimed to assess patient satisfaction, identify educational gaps, and explore communication challenges in dermatology clinics across Saudi Arabia. Patients and methodsA national cross-sectional survey was conducted among 976 dermatology patients. A structured questionnaire evaluated demographics, perceived knowledge, satisfaction with information provided, communication barriers, and preferred educational methods. Descriptive statistics and chi-square tests were used for analysis. ResultsAmong participants who had attended dermatology clinics (n = 795), 61.6% reported frequent or occasional confusion about their condition, and only 45.4% demonstrated high self-reported knowledge. Overall satisfaction was moderate, with 58.3% satisfied or very satisfied, while 9.9% reported dissatisfaction. The most reported communication barriers were limited consultation time (25.2%) and patient anxiety about asking questions (15.3%). Patients felt least informed about treatment options (22.6%), diagnosis (20.3%), and potential side effects (19.3%). Most participants (70.6%) preferred language communication to be in Arabic, and 78% favored the physical method of face-to-face education consultation. Patient knowledge, barriers and preferences significantly differed with age, gender, and condition complexity (p < 0.05). ConclusionDermatology patients in Saudi Arabia report moderate satisfaction with substantial educational needs and communication barriers. Addressing consultation time constraints, fostering supportive communication environments, and providing patient-centered, language-appropriate education; particularly through direct face-to-face interactions will aid to enhance understanding, satisfaction, and engagement in for an overall better provider-patient dermatologic care.

BackgroundNon-segmental vitiligo(NSV) shows marked heterogeneity in activity, progression, and treatment response. Reliable clinical markers that predict prognosis and patient-reported outcomes are lacking. ObjectivesTo identify clinicodemographic and clinical predictors of disease extent, progression, repigmentation, treatment dependency, noticeability, and psychosocial impact in NSV. MethodsIn this prospective cohort study, 275 patients with NSV were followed for 12 months. Sixteen baseline variables, including demographic features, autoimmune history, and clinical markers (koebnerization, confetti and trichrome patterns, leukotrichia, mucosal, acral, and periorificial involvement), were recorded. Outcomes included body surface area(BSA), progression, repigmentation, treatment dependency, Vitiligo Noticeability Scale(VNS), and quality-of-life indices(VIS-22, DLQI, C-DLQI, F-VIS). Multivariable analyses and cluster analysis were performed at 6 and 12 months. ResultsMarkers of disease activity leukotrichia, trichrome and confetti lesions, koebnerization, and mucosal, acral, and periorificial involvement were strongly associated with greater BSA, poor repigmentation, higher noticeability, and treatment dependency. Leukotrichia was consistent predictor of poor repigmentation and high VNS. Family history of autoimmunity predicted progression and treatment dependency. Early-onset vitiligo showed lower disease extent but greater family-related psychosocial burden. Cluster analysis identified severe, intermediate, and mild phenotypes with distinct therapeutic responses. ConclusionsSimple clinical markers can stratify NSV patients into prognostic subgroups, enabling individualized treatment and counseling. Plain Language SummaryVitiligo behave variably in different people, some people may have slow-spreading course, while others develop widespread or persistent patches. In this study, we followed 275 people with non-segmental vitiligo for one year to find signs on the skin that could predict how the disease would behave and how it would affect daily life. We found that features such as white hair within patches (leukotrichia), speckled (confetti) or three-colored lesions (trichrome), new patches appearing after injury (koebnerization), and involvement of the lips, mouth, hands, feet were linked to more severe disease, poorer response to treatment, and greater cosmetic concern. A family history of autoimmune disease increased the risk of worsening vitiligo. Patients who developed vitiligo early in life had less skin involvement but greater emotional and family-related impact. These easily recognized signs can help doctors and patients plan treatment and set realistic expectations. Significance of the studyNon-segmental vitiligo (NSV) has a heterogeneous and unpredictable clinical course with variable progression and response to therapy. However, robust prospective data linking these markers with long-term outcomes and patient-reported measures remain limited. In our prospective cohort of 275 patients, clinical markers such as leukotrichia, trichrome and confetti lesions, koebnerization, and acral/mucosal/periorificial involvement, were strongly associated with greater disease extent, poorer repigmentation, higher treatment dependency, and increased noticeability. Leukotrichia consistently predicted poor repigmentation. Thereby, prognostic stratification can also improve patient counselling regarding expected repigmentation, treatment duration, and psychosocial burden.

I.Cutaneous skin melanomas with wild-type BRAF alleles ("BRAF-WT melanomas") remain relatively difficult to treat, even though they typically possess driver mutations in a RAS gene or NF1. For example, these tumors respond relatively poorly to combinations of MEK and BRAF inhibitors, and their response to ICIs is muted compared to the response of BRAF-mutant melanomas. ERBB2 and ERBB4, which encode receptor tyrosine kinase genes, are necessary and sufficient for the proliferation of multiple BRAF-WT melanoma cell lines. Consequently, we have postulated that ERBB4-ERBB2 heterodimerization drives BRAF-WT melanomas. This mechanism is consistent with the observation that elevated ERBB4 transcription or ERBB4 mutations are found in a significant fraction of BRAF-WT melanoma tumor samples. Moreover, a subset of ERBB4 mutations found in BRAF-WT melanoma samples increases proliferation in a BRAF-WT melanoma cell line. Because the elevated ERBB4 transcription observed in BRAF- WT melanomas is typically insufficient to cause ligand-independent ERBB4 signaling, we have postulated that ligands for ERBB family receptors drive the elevated ERBB4-ERBB2 heterodimerization responsible for the proliferation of BRAF-WT melanoma cell lines. We have explored this hypothesis by analyzing data found in the Broad Institutes Cancer Cell Line Encyclopedia. These data suggest that some EGF family hormones are required for the proliferation of BRAF-WT melanoma cell lines. Likewise, the G11/Gq pathway, which can stimulate cleavage and maturation of EGF family hormones, is also required for the proliferation of BRAF-WT melanoma cell lines. Thus, these data suggest additional therapeutic targets in BRAF-WT melanomas. Moreover, because many uveal (ocular) melanomas possess elevated G11/Gq signaling, these data suggest that ligand stimulation of ERBB receptor signaling may contribute to uveal melanomagenesis or progression.

Background: Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease associated with clinical, psychosocial, and economic burden. Accurate severity assessment is essential for guiding treatment escalation and monitoring disease activity, yet clinician-based scoring systems such as the Eczema Area and Severity Index (EASI) are limited by subjectivity and considerable inter- and intra-rater variability. Erythema, a key driver of AD severity grading, is particularly prone to inconsistent evaluation due to differences in ambient lighting, device quality, skin tone, and rater experience, underscoring the need for objective, reproducible assessment tools. Objective: To develop and validate an artificial intelligence (AI) pipeline for grading erythema, excoriation, and lichenification severity in AD from clinical photographs. The study evaluated the level of agreement between AI severity ratings in each category against dermatologists, non-specialists, and a consensus reference standard, with erythema as the primary outcome of interest. Methods: A two-stage AI pipeline was developed using EfficientNet B7 convolutional neural networks (CNNs). The first CNN was trained as a binary AD classifier on 451 AD and 601 non-AD images for lesion detection and segmentation. The second CNN was trained on 173 dermatologist-annotated AD images which were scored on a 0-3 ordinal scale for erythema, excoriation, and lichenification. This CNN had a downstream feature extraction algorithms such red channel contrast for erythema, Law's E5L5 for excoriation, and S5L5 texture maps for lichenification. In a cross-sectional validation study, 41 independent test images were scored by two blinded dermatologists and two blinded physicians. AI predictions were compared to individual rater groups and mode-derived consensus scores using weighted Cohen's kappa, classification accuracy, confusion matrices, and error direction analyses. Results: On internal validation, the severity CNN achieved 84% overall accuracy (averaged across all three attributes), 86% sensitivity, 87% specificity, and a macro-averaged area under the receiver operating characteristic curve (AUC) of 0.90. In the external comparison with blinded human raters, erythema agreement between the AI and dermatologist consensus was substantial (accuracy 80.7%; kappa = 0.68), with no large (>2-point) misclassifications. Physician consensus agreement was lower (accuracy 54.8%; kappa = 0.34), reflecting greater variability among primary care physicians (non-specialists). For excoriation, AI-dermatologist agreement was moderate (accuracy 72.4%; kappa = 0.62); for lichenification, agreement was similar (accuracy 71.4%; kappa = 0.59). Across all features, disagreements were predominantly between adjacent severity categories. The AI was able to generate erythema severity grades for images of darker skin tones that dermatologists typically would not rate and were marked as "unable to assess". Limitations: The validation set was small (41 images), severe cases (score 3) were underrepresented, one rater participated in both training annotation and validation scoring, and sample size was insufficient for robust stratification by skin tone or body site. Conclusion: The AI pipeline demonstrated dermatologist-level accuracy for erythema scoring, consistent moderate agreement for excoriation and lichenification, and a potential advantage in assessing erythema on darker skin tones. These findings support its potential as a standardized, objective tool for AD severity assessment. Prospective validation in larger, more diverse cohorts is warranted.

BACKGROUND Erythema nodosum leprosum (ENL) is a severe inflammatory complication of leprosy associated with disability, morbidity and mortality. Impairment of health-related quality of life (HRQoL) in ENL has been reported using the Dermatology Life Quality Index (DLQI) and the 36-Item Short Form Health Survey (SF-36), the latter validated in people affected by leprosy. Understanding the correlation between these measures is important to determine whether the shorter dermatology-specific DLQI provides a valid and practical measure of HRQoL in ENL. OBJECTIVES To examine the relationship between DLQI and SF-36 scores in individuals with ENL using data from the Methotrexate and Prednisolone study in ENL (MaPs in ENL). METHODS A post-hoc analysis of prospectively collected HRQoL data from the trial sites in India, Indonesia, and Nepal of the MaPs in ENL multicentre randomised clinical trial was performed. HRQoL was assessed using the DLQI and SF-36 at enrolment and at weeks 24, 48 and 60. Associations between DLQI and SF-36 physical (PCS) and mental (MCS) component summary scores were evaluated using correlation analyses and multivariable linear regression at enrolment, and linear mixed-effects models during follow-up adjusted for age, sex, recruiting centre and enrolment SF-36 scores. RESULTS A total of 383 paired HRQoL assessments from 129 participants were analysed. At enrolment, HRQoL impairment was substantial (median DLQI 19, IQR 15-21; mean PCS 30.3 + - 7.3; mean MCS 33.3 + - 8.4). DLQI scores improved markedly during follow-up. Across all timepoints, DLQI was strongly inversely correlated with PCS and MCS (both p<0.001). In adjusted analyses, higher DLQI scores were consistently associated with lower PCS and MCS. At enrolment, each 1-point increase in DLQI was associated with a 0.66-point reduction in PCS and a 0.51-point reduction in MCS (both p<0.001). These associations remained strong during follow-up, with no evidence that they varied over time. CONCLUSIONS DLQI scores were strongly and consistently associated with SF-36 physical and mental health scores. These findings support the use of the DLQI as a practical patient reported outcome measure to assess the HRQoL associated with ENL and its change following treatment.

Lichen Planopilaris (LPP) is a lymphocyte-mediated scarring alopecia characterized by progressive follicular destruction and fibrosis. In this clinical trial, patients with biopsy proven LPP were treated with deucravacitinib (an oral inhibitor of tyrosine kinase 2 (TYK2)) 6 mg BID for 24 weeks (NCT-06091956). Bulk and single-cell RNA sequencing was performed on paired pre- and post-treatment scalp biopsies from baseline and week 4. Patients (N=10) demonstrated improvements in PGA (88.9%, p=0.008), LPPAI (-2.3 points, SD 1.1, p=0.002) and Skindex-16 (-21.0 points, SD 22.1, p=0.014) scores at week 24. Bulk transcriptomic analysis of untreated LPP revealed upregulation of type I Interferon (IFN)-stimulated genes and pathways related to inflammation, immune activation, keratinization, and extracellular matrix remodelling, with downregulation of immune and inflammatory pathways following treatment. Single-cell RNA-seq of LPP was characterized by enrichment of CD8+GZMK+ T cells which showed downregulation of T-cell receptor signaling as well as antiviral pathways with treatment. Basal keratinocytes exhibited reduced cytokine and interferon signaling and decreased communication with NK cells following treatment. CCL19+ fibroblasts were prominent in untreated disease was attenuated after treatment, with downregulation of type I IFN signaling. Selective TYK2 inhibition with deucravacitinib effectively suppresses these inflammatory circuits in LPP and represents a promising therapeutic strategy.

Hidradenitis suppurativa (HS) is a chronic, debilitating, inflammatory skin disorder. Medications have been reported in association with cases of new-onset HS or exacerbation of existing disease; however, the extent of this risk is unclear. We queried the FDA adverse event reporting system (FAERS) from 2003-2023 to identify drug-specific reporting signals for HS. We stratified reports by whether HS was listed as an indication (Drug-Worsened, DW) or not (Drug-Induced, DI) to distinguish disease flares from de novo disease. Primary suspect drugs with > 3 HS reports were included. Disproportionality was quantified using reporting odds ratio (ROR) with Wald 95% confidence intervals (CI). Time-to-onset was also evaluated. We identified 5,529 HS reports: 3,725 DW and 1,804 DI. Females comprised 63% (mean age 41) and the US was the top reporting country (81.8% DW; 53.66% DI). In the DI group, statistically significant signals were observed for immunomodulators also used to treat HS including adalimumab (n=506, ROR= 12.6 [11.3-14.0]) infliximab (n=108, ROR=8.2 [6.7-10.0]), and secukinumab (n=79, ROR=6.6 [5.2-8.2]), consistent with paradoxical reactions. Median time-to-onset was 22 days for secukinumab, compared to 312 and 319 days for adalimumab and infliximab. Signals were also identified for isotretinoin (n=28, ROR= 6.2 [4.2-8.9]), and for antineoplastic agents including cytarabine (n=25, ROR= 24.7 [16.6-36.6]) and omacetaxine (n=8; ROR= 7416 [CI 2923-18816]), which may reflect reported eccrine hidradenitis. In the DW group, adalimumab (n=2967), secukinumab (n=67), and infliximab (n=57) predominated but displayed lower RORs (0.72-1.4), likely reflecting indication bias. While mechanisms of drug-associated HS require further clarification, our findings demonstrate significant associations and highlight the importance of dermatologic monitoring when initiating certain agents.

In mice, oral epithelial stem cells (OESCs) are essential for oral mucosal homeostasis and repair. Less is known regarding the role of OESCs in the human oral mucosa. Here, we studied the behaviour of OESCs and their contribution to tissue maintenance and repair in oral lichen planus (OLP). OLP is a chronic T cell-mediated disease characterized by basal keratinocyte degeneration, epithelial atrophy, acanthosis, and hyperkeratosis. Using immunohistological techniques and semi-automated image analysis, we observed that in OLP proliferative activity was increased in the normally largely quiescent basal cell compartment. In areas of OLP mucosa with intact basal cell layer, expression of NGFR, KRT15, and KRT19-markers of slowly cycling reserve OESCs, was strongly reduced or absent. In contrast, expression of CSPG4, a marker for actively cycling stem cells, was increased in OLP basal cells. Tissue compartmentalization, as evaluated by keratin expression, was strongly disturbed. Taken together, our findings indicate that the inflammation in OLP leads to activation and proliferation of OESCs that give rise to a population of cells with an aberrant differentiation programme. Along with the well-documented epithelial up-regulation of anti-apoptotic proteins in OLP, this likely reflects an attempt by the epithelium to avoid overt ulceration.

Stem cell niches are dynamic microenvironments that regulate tissue homeostasis. Epidermal stem cells (EpiSC) preferentially localize to concave regions of epidermal rete ridges, which serve as primary niches for stem cell maintenance. EpiSC number and functional integrity decline during chronological aging. A defining feature of aged skin is epidermal atrophy, in which the prominent rete ridges present in young skin become flattened. Whether such topographical alterations influence EpiSC homeostasis and differentiation remains unclear. To address this, we generated anatomically accurate rete ridge structures using 3D bioprinting of collagen matrices as an ex vivo model and compared EpiSC cultured within concave topography to those maintained on a flat matrix resembling aged skin. Transcriptomic analysis revealed that concave niches promoted keratinocyte differentiation, marked by increased type I and II keratin gene expression and downregulation of cell cycle-associated genes. ATAC-seq identified topography-dependent chromatin accessibility changes enriched for transcription factors regulating epidermal differentiation, including upregulation of KLF4 and GRHL3 and downregulation of SOX9, HOXA1, and ETS1. Consistently, aged human skin showed reduced KLF4 and GRHL3 and increased SOX9 compared with young skin. Our findings demonstrate that concave niche topography imposes a spatially defined EpiSC microenvironment that promotes differentiation, alters cell cycle, and when perturbed, potentially contributes to the aging process. We conclude that spatial localization within rete ridge regions significantly affects epidermal progenitor stemness properties as fundamental differences in the physical microenvironment appear to influence cell fate decisions, thus, form shapes function of EpiSC.

Background: Microbiota dysbiosis of the skin has been implicated in ulcer formation. Individuals with diabetes remain at high risk for diabetic foot ulcers (DFUs) even after ulcer healing. Topical chlorhexidine gluconate (CHG) is a broad-spectrum antiseptic commonly used to reduce microbial burden. In a prior randomized clinical trial comparing daily CHG foot treatment with soap-and-water treatment, no statistically significant reduction in new DFUs was observed, prompting evaluation of whether CHG produced durable changes in the skin microbiota. Objective: To compare changes in foot skin microbiota (including bacterial bioburden, diversity, and community composition) associated with daily CHG versus soap-and-water use over one year in people with diabetes and prior foot complications. Methods: In a single-center, double-blind, placebo-controlled randomized trial, 87 participants were randomized to daily CHG wipes or soap-and-water wipes for 12 months. Foot swabs were collected at baseline, 3 and 12 months, and 4 weeks post-treatment. Bacterial bioburden was quantified. Microbiota composition was assessed using 16S rRNA and ITS amplicon sequencing. Key Results: CHG treatment significantly reduced bacterial bioburden, increased microbial diversity, and altered community composition, including sustained reductions in Staphylococcus abundance. Several microbiota changes persisted more than 4 weeks after treatment cessation. Soap-and-water treatment showed similar but smaller and largely nonsignificant trends. Conclusions: Daily CHG use durably modifies foot skin microbiota in high-risk individuals with diabetes. However, this alone may be insufficient to prevent new foot complications, highlighting the need for additional interventions. These findings have implications for long-term CHG use in populations at risk for staphylococcal infections.

Mesenchymal stem cells (MSCs) have garnered significant attention over the past three decades due to their robust regenerative potential, primarily mediated by their paracrine activity by releasing soluble bioactive factors and extracellular vesicles (EVs). The MSC secretome plays a pivotal role in wound healing by influencing cellular migration, inflammation, angiogenesis, extracellular matrix (ECM) remodeling, and re-epithelialization. SPARC (Secreted Protein Acidic and Rich in Cysteine), a multifunctional ECM glycoprotein involved in tissue repair and remodeling, regulates key processes such as cell migration, proliferation, angiogenesis, and survival. Despite its known role in ECM dynamics, the impact of SPARC expression on the regenerative properties of MSCs remains underexplored. In this study, we hypothesized that SPARC overexpression in MSCs enhances their secretomes regenerative capacity. Using lentiviral systems, we generated SPARC-overexpressing (+SPARC) and SPARC-knockdown (KD-SPARC) MSCs to investigate SPARCs role in wound healing. Conditioned media (CM) derived from these MSCs were analyzed in vitro for their effects on human skin keratinocytes and fibroblasts. Our results revealed that SPARC expression significantly influences cell-specific migration and cell cycle. Furthermore, in an in vivo wound healing model, CM from +SPARC MSCs accelerated regeneration, while SPARC absence in MSCs CM delayed the healing process. These findings underscore the critical role of SPARC in modulating MSC secretome composition and enhancing its regenerative efficacy. This study highlights SPARC as a promising therapeutic target for the development of advanced regenerative therapies aimed at improving cutaneous wound healing outcomes.

Vitiligo is an autoimmune disorder characterized by melanocyte destruction. We performed a rank-based meta-analysis of six independent transcriptomic studies (115 samples) spanning microarray, bulk and single-cell RNA-seq platforms to identify consensus signatures of lesional skin. Robust Rank Aggregation identified 114 differentially expressed genes (FDR < 0.05) with striking asymmetry: 108 downregulated versus 6 upregulated. Downregulated genes were dominated by melanocyte markers (MLANA, TYRP1, DCT, PMEL, KIT). Upregulated genes included interferon-stimulated genes (OAS1, OAS2, EPSTI1). Pathway-level meta-analysis confirmed uniform suppression of melanogenesis, while immune activation was heterogeneous across datasets. Single-cell data from three included studies confirmed melanocyte depletion. The 108 downregulated genes showed exclusive expression in melanocytes. These include neural genes (PLP1, GPM6B, NRXN3), consistent with melanocytes neural crest origin. We also identified candidate melanocyte markers such as CYB561A3 and QPCT with high melanocyte specificity and consistent downregulation in vitiligo. These findings reveal a robust melanocyte loss signature in vitiligo detectable across all platforms, and study-dependent immune activation possibly influenced by sampling method and disease characteristics.

BackgroundLasers have wide applications in medicine and dermatology, but are associated with pain and anxiety, particularly in younger patients. Pain mitigation is often limited to topical anesthetics in the outpatient setting. Distraction techniques are limited by the need for ocular protection, which can include adhesive eye patches that can completely occlude vision. Virtual reality is effective at managing procedural pain and anxiety under other short medical procedures and is a promising tool for this population. ObjectiveThis trial aims to assess the safety, feasibility, and efficacy of Virtual Reality Pain Alleviation Therapeutic (VR-PAT) for pain management during outpatient laser procedures. Methods40 patients requiring outpatient laser therapy for at least two sessions will be recruited from a pediatric hospital in the midwestern United States for this crossover randomized, two-arm clinical trial with a 1:1 allocation ratio. During the first laser visit, the participant will be randomly assigned to either play the VR-PAT game during their procedure or wear the headset with a dark screen. Participants will answer questions about their pain (Numeric Rating Scale (NRS) 0-10), anxiety (State Trait Anxiety Inventory for Children, NRS 0-10, Modified Yale Preoperative Anxiety Scale (mYPAS)), and pain medication usage. Those playing the VR-PAT will additionally report simulator sickness symptoms and their experience playing the game. At their second laser visit, participants will crossover to the opposite intervention from their first visit. The primary outcomes are the difference in self-reported pain and anxiety between the two interventions. Feasibility outcomes include the proportion of screened patients who are eligible, consent, and complete both visits and adverse events reported. To evaluate the efficacy of pain reduction, composite scores of pain score, pain medication will be calculated for each laser visit. To evaluate the efficacy of anxiety reduction, the change of mYPAS scores will be compared between control and VR groups at each visit using Wilcoxon rank sum tests. All statistical analyses will follow the intention-to-treat principle in regard to intervention assignment at each visit. ResultsThe study was funded in January 2023 and began enrollment at that time. A total of n=44 participants were recruited and data collection was completed in November 2025, with n=40 subjects completing both visits. The sample was balanced with n=40 subjects using the intervention and participating in the control condition. The age range of the complete sample was 6 to 21 years at recruitment and was 55% female sex. Data analysis is in progress with final results planned for June 2026. ConclusionsFindings from this innovative randomized clinical trial will provide early evidence on the efficacy of the VR-PAT for reducing self-reported pain and anxiety during outpatient laser procedures. The results from this trial will inform a large-scale, multisite study. Trial RegistrationClinicalTrials.gov: NCT05645224 [https://clinicaltrials.gov/study/NCT05645224]

Social stigma surrounding chronic skin Ulcer leads patients to hide their wounds or delay seeking medical care. The aim of this study was to explore the types and causes of chronic skin ulcers among patients seen in the dermatology departments of two university hospitals in Burkina Faso. This was a cross-sectional, retrospective study covering an 11-year period, from 2013 to 2023. A review of consultation records allowed for the collection of sociodemographic and clinical data from 104 patients who were seen for chronic skin ulcers over the 11-year period, averaging 9 patients per year. The patients were primarily adults (n=60) and older adults (n=21). Leg ulcers were the condition observed in most patients (n=59). Eight cases of Buruli ulcer (7.69%) were identified among the 104 patients. Five of the eight cases, or 62.50%, were aged between 0 and 19 years. Half of the eight patients resided in Ouagadougou. These results highlight low utilization of dermatology services for chronic skin ulcers. Furthermore, indigenous cases of Buruli ulcer have been identified in Burkina Faso. Consequently, our findings call for the implementation of strategies focused on addressing social perceptions of these ulcers and on the screening and management of this disease.