British Journal of Dermatology

Palmoplantar pustulosis (PPP) and dyshidrotic eczema (DE) are chronic vesiculopustular dermatoses with overlapping clinical presentations but distinct underlying biology. Although comparative transcriptomic and proteomic analyses between PPP and DE have been reported, they remain limited in number and scope, with no comprehensive understanding of their distinct molecular signatures. Moreover, their molecular mechanisms remain unclear, and currently available therapeutic options are limited. To clarify disease-specific epidermal programs underlying vesicle formation, we conducted Visium HD spatial transcriptomic analysis of FFPE lesional skin samples obtained from patients with PPP and DE, followed by immunohistochemical validation against normal palmoplantar skin controls. Spatial clustering identified a keratinocyte subpopulation adjacent to vesicles that exhibited distinct transcriptional programs in the two diseases. In PPP, vesicle-associated keratinocytes demonstrated marked downregulation of aquaporin-3 (AQP3) and E-cadherin, together with strong, spatially localized activation of JAK-STAT3 signaling. Conversely, DE exhibited diffuse AQP3 expression and more homogeneous activation of JAK-STAT3 signaling throughout the epidermis. These results indicate that, although PPP and DE share inflammatory pathways, they differ substantially in their spatial molecular architecture. Reduced AQP3 expression and localized STAT3 activation may contribute to vesicle formation in PPP, supporting our previous hypothesis that implicates intraepidermal sweat leakage as a pathogenic mechanism in PPP. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/723901v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@19c7591org.highwire.dtl.DTLVardef@eab29aorg.highwire.dtl.DTLVardef@73c2e2org.highwire.dtl.DTLVardef@1ffc02f_HPS_FORMAT_FIGEXP M_FIG C_FIG

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.

BackgroundIn the Melanoma Genomics Managing Your Risk Study, access to personal genomic risk testing led to improvements in some melanoma prevention and early detection behaviors. PurposeWe aimed to examine the hypothesized psychosocial mediators of the effects observed in the trial. MethodsAustralians of European ancestry without melanoma and aged 18-69 years were recruited via the national Medicare database and randomized to receive personal genomic risk information or usual care (N=1,025). Questionnaires were administered at baseline, 1-month post-intervention, and 12-months post-baseline to assess self-reported prevention and early detection behaviors and psychosocial measures. To identify potential mediators, we first evaluated the interventions effect on psychosocial measures and the associations between psychosocial measures and behavioral outcomes. We then estimated the natural indirect effects (NIEs) and their 95% confidence intervals (CIs) to quantify the effects mediated by potential mediators identified. ResultsAmong participants with high traditional melanoma risk, the interventions effect on increased sun protection at 1-month was partially mediated by changes in perceived importance [NIE mean difference (95% CI): 0.02 (0.00, 0.04)] and perceived effectiveness [0.01 (0.00, 0.03)] of sun protection strategies. Among women, the interventions effect on increased whole-body skin examinations at 1-month was partially mediated by perceived capability to engage in skin examinations [NIE odds ratio (95% CI): 1.08 (1.00, 1.29)] and perceived control over detecting a future melanoma [1.13 (1.03, 1.32)]. ConclusionsThe effectiveness of precision prevention and early detection interventions may be enhanced by targeting key psychosocial mediators through tailored communication of personal melanoma risk.

Importance: Enfortumab vedotin (EV) is an antibody-drug conjugate approved for the treatment of locally advanced or metastatic urothelial cancer (la/mUC). Cutaneous adverse events (cAEs) are common during EV therapy, with prior studies suggesting an association between EV-related cAEs and improved survival; however, there is insufficient data to delineate the survival benefit of EV-induced cAEs from those associated with concurrent immune checkpoint inhibitors (ICIs). Objective: This study aims to evaluate the association of EV-induced cAEs and survival, and to characterize the timing and morphology of EV-induced cAEs. Design: We conducted a multi-institutional retrospective study of patients with la/mUC treated with EV between 2020 and 2025. Setting: Multicenter academic referral center. Participants: A total of 449 EV-treated patients were included. Patient characteristics were extracted manually, and likelihood scoring was used to attribute cAEs to either EV or other etiologies. Exposure: EV treatment. Main Outcomes and Measures: We estimated progression-free (PFS) and overall (OS) survival using Kaplan-Meier method. Multivariable time-varying and landmark Cox regression models were used to evaluate associations between EV-induced cAE and survival. Sensitivity analyses were performed at landmarks from 15 to 105 days. Results: Of 449 patients, 206 (45.9%) developed a cAE; 39 (18.9%) were high-grade and 127 (61.7%) were attributed to EV. The most common cAEs were pruritus (41.3%), unspecified and desquamating dermatitis (37.3%), and morbilliform dermatitis (27.7%). Across all treatment groups, survival was longer in patients with EV-induced cAEs. Developing an EV-induced cAE was protective across all examined landmark times, with hazard ratio (HR) 0.60 (95% CI: 0.43-0.82, p<0.001) for PFS and HR 0.46 (95% CI: 0.31-0.67, p<0.001) for OS at primary landmark time of 30 days. Early-onset EV-induced cAEs were protective at all landmark times and high-grade EV-induced cAEs were not associated with worse survival. Conclusions and Relevance: EV-induced cAEs were independently associated with improved PFS and OS in patients with la/mUC, even after accounting for immortal time bias and ICI exposure. Distinguishing EV-induced cAEs from other etiologies in timeline and morphology may help guide oncology and dermatology management.

Keloids are fibroproliferative skin disorders arising following dermal injury that extend beyond the original wound margins. Their pathogenesis remains poorly understood, and current treatments are associated with high recurrence rates. Identifying transcriptomic biomarkers that distinguish keloids from other skin and scar phenotypes may provide insight into disease mechanisms and facilitate the development of targeted therapeutic approaches. However, previous transcriptomic studies have often been limited by small sample sizes, pairwise comparisons between tissue classes, heterogeneous data-integration strategies, and a reliance on conventional differential gene expression (DGE) analysis. Here, we employed a multi-stage machine learning (ML) workflow for robust keloid biomarker discovery using transcriptomic datasets derived from both bulk RNA sequencing and single-cell RNA sequencing (scRNA-seq). We assembled and harmonized, to the best of our knowledge, the largest curated cross-study keloid transcriptomic cohort currently available, comprising 81 samples from 13 independent studies spanning four clinically relevant tissue classes: normal skin, normotrophic scar, hypertrophic scar, and keloid scar. Through study-aware cross-validation, feature selection, partition-stability analysis, and bootstrap validation across multiple ML classifiers, we identified a panel of eight highly consistent biomarkers capable of distinguishing keloid from non-keloid samples. These biomarkers were associated with dysregulation of extracellular matrix homeostasis, fibrosis-resolution pathways, vascular remodelling, and metabolic reprogramming. Comparison with conventional DGE analysis demonstrated substantial agreement while also highlighting important differences between the two approaches. In particular, FASN was consistently identified by the ML workflow as an upregulated discriminatory biomarker despite exhibiting weak, non-significant differential expression in the DGE analysis. Cell-type-specific analysis further supported this finding, revealing significant FASN upregulation in fibroblast and vascular endothelial populations. These results demonstrate that ML and DGE capture complementary aspects of transcriptomic variation. This study provides a robust strategy for cross-study transcriptomic biomarker discovery and identifies candidate genes and pathways for future mechanistic and therapeutic investigation in keloids. 1 Author SummaryKeloids are abnormal scars that continue to grow beyond the original wound and can be difficult to treat because they frequently recur after therapy. Although many studies have investigated the biology of keloids, the molecular mechanisms that distinguish them from other scar types remain incompletely understood. Identifying biomarkers involved in keloid formation may help inform improved treatment strategies. Previous transcriptomic studies have often been limited by small sample sizes and inconsistent analytical approaches. In this study, we combined gene-expression data from multiple independent studies to create, to the best of our knowledge, the largest cross-study transcriptomic collection available for keloid analysis. We then applied several machine learning approaches to identify genes that consistently distinguished keloids from other skin and scar phenotypes. The identified biomarkers were associated with extracellular matrix remodeling, fibrosis, vascular function, and cellular metabolism. One gene involved in fatty-acid synthesis, FASN, was repeatedly identified by the machine learning analyses despite being overlooked by conventional gene-expression methods. Additional single-cell analyses confirmed elevated FASN expression in specific cell populations within keloid tissue. More broadly, this work provides a strategy for discovering robust biomarkers from heterogeneous biological datasets and identifies molecular targets for future studies of keloid disease.

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.

Cutaneous squamous cell carcinoma (cSCC) is a common skin cancer associated with substantial morbidity and mortality in advanced stages. Despite its well-described stepwise progression from actinic keratosis to invasive disease, robust molecular markers for stage discrimination and clinical decision-making remain limited. We sought to define the transcriptional continuum underlying cSCC progression, identify stage-associated biomarkers, and assess the broader relevance of these programs across human malignancies. Bulk RNA sequencing (HTG EdgeSeq) and spatial transcriptomics (GeoMx) were performed on biopsies from eight patients, each presenting multiple disease stages (healthy skin, premalignant lesion, tumor core, and invasive front) within the same lesion field, enabling within-patient analysis of progression. Spatial transcriptomic analyses identified more than 2,000 differentially expressed genes whose expression varied across disease stages. These genes were organized into 18 coordinated expression programs reflecting progressive biological rewiring during tumor evolution. Proliferation, extracellular matrix remodeling, inflammation, and stress-response pathways were progressively upregulated, whereas epithelial differentiation and metabolic processes, including lipid and amino acid metabolism, were downregulated. Macrophages exhibited distinct metabolic reprogramming, with increased purine metabolism, glycolysis, and pyruvate metabolism across progression. To evaluate the broader clinical relevance of these progression-associated programs, we developed a reproducible Snakemake pipeline to systematically screen 32 solid and hematologic malignancies from The Cancer Genome Atlas (TCGA). A combined cSCC-progression signature was significantly associated with poor overall survival (P < 0.05) in 10 additional cancer types. Finally, we identified 12 stage-informative biomarkers, whose spatially restricted expression patterns were validated using Visium HD. This study provides a spatially resolved and stage-aware transcriptomic map of cSCC progression, identifies coordinated gene programs underlying disease evolution, and defines progression-associated signatures with prognostic relevance across multiple cancers, highlighting their potential translational value.

Cutaneous squamous cell carcinoma (cSCC) represents a growing public health burden, with incidence projected to increase 23-29% over the coming decade. Topical immunoprevention strategies targeting the PD-L1/PD-1 and TLR4 axes have demonstrated preclinical efficacy, yet optimal intervention timing in humans remains undefined. To address this gap, single-cell RNA sequencing was performed on matched sun-protected (SP), sun-damaged (SD), and actinic keratosis (AK) biopsies from the same individuals, along with independent cSCC cases. Immune checkpoint and innate inflammatory signals were detectable as early as SD skin, prior to histologically confirmed dysplasia. Monotonically increasing expression of CD274 (PD-L1), CTLA4, PDCD1, CD27, and STAT1, alongside progressive TLR4-MYD88 innate immune signaling, was revealed through pseudobulk data analysis, with earliest upregulation at the SD stage. Fuzzy c-means trajectory clustering identified cell-typespecific programs across dendritic cells, macrophages, T cells, fibroblasts, endothelial cells, and keratinocytes. Dendritic cells shifted from early inflammatory antigen-presenting programs toward late PD-L1/IFN-regulatory states; macrophages showed monotonically increasing TLR4-associated myeloid activation; and T cells defined a "hot but exhausted" microenvironment in established cSCC. These findings identify SD and AK as biologically active stages for topical immunoprevention and provide a cellular roadmap for PD-L1/PD-1 and TLR4 blockade strategies.

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.

BackgroundCutaneous squamous cell carcinoma (cSCC) is among the most common human cancers, yet the cellular identity and molecular programs of its preinvasive precursor, actinic keratosis (AK), remains poorly defined. MethodsWe applied CITE-seq to patient-matched AK, UV-exposed normal skin, and non-UV-exposed normal skin (n=5 patients, 12 biopsies) and performed spatial whole-transcriptome profiling in an independent cohort (n=4) to map pre-invasive keratinocyte states at single-cell resolution. ResultsWe identify AK-specific keratinocytes (ASK), a discrete population localized to the dysplastic basal epidermis and characterized by UV-associated mutational signatures (SBS7b), high mutational burden, and recurrent copy number alterations including 9p loss and 8q gain. ASK occupies a basal-like undifferentiated state sustained by a {Delta}Np63/PITX1 regulatory module that attenuates Notch/HES1-driven differentiation and activates glycolytic metabolism. Comparison with published cSCC data reveals that ASK share core tumor-propagating gene networks with tumor-specific keratinocytes (TSK), including IGFBP6, IGFBP2, and ITGA6, but lack invasion effectors MMP1, MMP10, and PTHLH. Functional experiments identify IGFBP6 as a pro-proliferative factor in AK-derived keratinocytes. The AK microenvironment shows expansion of inflammatory basal keratinocytes, barrier disruption, and early immunosuppressive T cell remodeling. ConclusionsThese findings define the molecular identity of a pre-invasive malignant keratinocyte population governed by p63/PITX1 and distinguish early oncogenic programs shared with invasive cSCC from later-acquired invasion effectors, identifying candidate targets for prevention or treatment of squamous cell carcinoma.

Deleterious CDKN2A germline variants account for ~40% of familial melanoma cases, while rare variants in CDK4, BAP1, and telomere-maintenance genes collectively attribute ~10% of familial risk. We sought to identify new high-penetrance susceptibility variants by sequencing 305 melanoma cases from 89 multi-case families negative for known predisposition gene variants. In one family, cutaneous melanoma co-segregated with a rare variant in DMRTA1 (p.Glu383Gln), located less than 480 kb upstream of CDKN2A on chromosome 9. Whole-genome sequencing then revealed an intergenic 234kb deletion that co-segregated with melanoma in 18 out of 21 cases across four generations. Further investigations revealed a further 10 families carrying this deletion, co-segregating with melanoma. The deleted region was predicted to encompass regulatory sequences and to interact with the CDKN2A promoter region. Tiled CRISPR inhibition of the predicted enhancer region confirmed interactions between the distant upstream deletion with CDKN2A resulting in decreased p16 transcript mRNA expression. Deletion carriers exhibited nearcomplete loss of p16 mRNA expression from the affected chromosome. This distant noncoding deletion is one of the most common founder variants predisposing to melanoma and reveals a new mechanism controlling p16 expression. Routine screening for this deletion in individuals with perceived high risk of melanoma is warranted.

Psoriasis is a chronic inflammatory skin disease characterized by keratinocyte hyperproliferation and immune dysregulation. Emerging clinical and experimental evidence suggests that endogenous lipid (endolipid) signaling systems, including the endocannabinoid system (ECS), represent a promising therapeutic target to treat psoriasis; however, comprehensive characterization of small-molecule endolipids and related proteins in psoriatic skin and their relationship to systemic changes remains limited. Here, we used the imiquimod (IMQ)-induced mouse model of psoriasis to perform combined lipidomic and transcriptional profiling of endolipid signaling in both skin and plasma. Targeted lipidomics revealed a striking divergence between tissues: most endolipids increased in inflamed skin but decreased in plasma, including the canonical ECS lipids anandamide and 2-arachidonoylglycerol. In contrast, selected lipid species, including taurine-conjugated metabolites (both N-acyl taurines and bile acids), were elevated in both tissues, indicating pathway-specific regulation. Targeted transcriptional analysis of whole skin showed reduced expression of key endolipid biosynthetic enzymes (Napepld, Dagla, Daglb) and the cannabinoid receptor Cnr1, while Cnr2 and ECS-related metabolic enzymes remained unchanged. Additional alterations were observed in transcripts involved in related endolipid signaling (Trpv1, Trpv4, Ppara, Pparg, Gpr55), bile acid metabolism (Fxr, Bsep, Fabp4, Fabp5, Cyp27a1, Cyp8b1), and inflammatory pathways (Cox-2). To resolve this apparent discrepancy between lipid levels and gene expression, we performed compartment-specific analyses of epidermal and dermal layers. These revealed a predominantly suppressive epidermal response across multiple ECS-related proteins, contrasted by a more variable dermal profile with selective preservation or upregulation, particularly of Cnr2. Together, these findings demonstrate that psoriasiform inflammation is associated with compartment-specific remodeling of endolipid signaling across skin and systemic compartments, underscoring the functional heterogeneity of epidermal and dermal layers. This dataset provides novel insights into the dysregulation of endolipid signaling systems in psoriasis and provides a foundation for the development of spatially informed, lipid-based therapeutic strategies.

How the cutaneous microenvironment influences early melanomagenesis is poorly understood. Here, we assessed the effects of three immune perturbations on premalignant melanocyte expansion in an autochthonous mouse model of disease. Depletion of regulatory T (Treg) cells markedly accelerated melanoproliferation, an unexpected phenotype that was associated with monocyte and macrophage infiltration, the production of inflammatory and angiogenic factors, and vascular leakage. In line with these observations, single cell transcriptomic analysis of Treg cell deficient skin revealed robust accumulation of monocyte-derived macrophages with tissue remodeling characteristics. Acute UV irradiation and 2,4-dinitrofluorobenzene (DNFB)-induced contact hypersensitivity had analogous effects on both the cellular microenvironment of the skin and the expansion of local premalignant melanocytes. Treatment with the anti-inflammatory agent dexamethasone attenuated DNFB-induced melanocyte expansion and vascular remodeling. Collectively, these results identify a conserved inflammatory axis linked to the early outgrowth of oncogenic melanocytes in the skin.

Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (SCC) are the most common keratinocyte-derived malignancies, yet they differ markedly in invasiveness, metastatic potential, and immune contexture. Although cancer-associated fibroblasts (CAFs) are increasingly recognized as key regulators of tumor architecture and tumor immunity, the spatial organization of distinct CAF subtypes in cutaneous carcinomas and their functional relationship with immune cells remains incompletely understood. Using a 33-plex imaging mass cytometry (IMC) panel, we profiled 28 regions of interest (ROIs) from 17 human BCC and SCC specimens, encompassing more than 739,000 single cells, and integrated these data with RNA fluorescence in situ hybridization (RNA-FISH), immunohistochemistry (IHC), multiplex immunofluorescence, and in vitro functional assays. We identified four fibroblast populations, including immunomodulatory CAFs (iCAFs), matrix CAFs (mCAFs), myofibroblast-like CAFs (myoCAFs), and reticular fibroblasts (retFIBs), and found that aggressive tumor subtypes were characterized by increased stromal area, extracellular matrix deposition, and altered CAF composition. CAF composition differed most prominently across BCC subtypes, with nodular BCC enriched for mCAFs and infiltrative BCC showing increased myoCAF density, consistent with a shift toward a contractile stromal program. Spatial analyses revealed distinct CAF-immune niches: iCAFs localized to immune-cell-rich, inflamed niches enriched for activated and/or exhaustion-associated immune-cell marker programs, whereas myoCAFs occupied fibroblast-dense, immune-poor niches with globally reduced immune activation. mCAFs were preferentially associated with immune cell accumulation in the stroma and spatial immune compartmentalization, with limited immune cell presence within tumor nests. At the invasive front, CAF-immune coupling was highly subset-dependent, with iCAFs linked to antigen-experienced T-cell states and myoCAFs linked to immune exclusion. In vitro, patient-derived CAF cultures from myoCAF-rich biopsies showed enhanced collagen-gel contraction, with cultures enriched for MCAM+ CAFs displaying increased contractile capacity. Aggressive tumor variants displayed increased stromal nuclear YAP/TAZ, while complementary single-cell pathway analysis supported a mechanically remodeled stromal microenvironment in which mCAFs contribute ECM/matrix-remodeling programs and RGS5/myoCAF-like populations show enhanced mechanotransduction-associated signaling, rather than a uniform CAF-wide increase in canonical YAP/TAZ transcriptional output. Together, these findings define spatially organized CAF programs in cutaneous carcinomas and identify myoCAF-rich stromal niches as a recurrent feature of aggressive, immune-repressed tumor architecture. These results nominate CAF composition as a biomarker of immune architecture and a potential determinant of therapeutic response.

Background: Cutaneous squamous cell carcinoma (cSCC) accounts for a significant proportion of skin malignancies in India, yet data on patterns of failure, particularly for extremity and truncal primaries remain scarce. We audited a decade of surgically treated cSCC at a tertiary cancer center to characterize failure patterns and associated risk factors. Methods: This retrospective study included 161 patients with histopathologically confirmed cSCC treated surgically between January 2013 and December 2023, comprising 127 upfront/residual and 34 recurrent presentations. Primary sites were extremities (64%), head and neck (26%) and torso (10%). 21 patients had Marjolin's ulcer. Outcomes included local, regional and distant failure, recurrence-free survival and overall survival. Brigham and Women's Hospital (BWH) staging was applied to assess prognostic utility. Statistical analysis was done using Kaplan-Meier and competing-risk methods. Results: Median follow-up was 2.4 years. Regional recurrence was the predominant failure pattern seen in 26 patients, local recurrence was seen in 14 patients and distant metastasis in 13. The 3-year cumulative incidences of local, regional and distant failure were 11%, 19% and 8.4% respectively. Rates of regional recurrence were substantially higher than Western series. Extremity primaries accounted for 19/26 regional recurrences. BWH T2b disease showed the highest regional failure rate (27.6%), exceeding T3 (17.8%) and T2a (6%) with perineural invasion significantly associated with regional failure in T2b/T3 tumors (p<0.001). Median time to regional metastasis was 8.4 months. At 3 years, overall survival was 77% and progression-free survival was 64%. Conclusion: Regional recurrence is the dominant mode of failure in this cohort, at rates higher than most published series, with extremity primaries and BWH T2b staging identifying particularly high-risk subgroups. These findings highlight the need for a comprehensive staging system encompassing non head and neck cSCC and support prospective evaluation of elective nodal staging and adjuvant radiotherapy in high-risk patients, alongside intensified surveillance.

Oculocutaneous albinism type 1 (OCA1) is a pigmentation disorder caused by biallelic tyrosinase (TYR) mutations, an essential enzyme for melanin synthesis. TYR inactivity results in loss of hair, skin, and eye pigment, which is detrimental for ocular function. Hypopigmentation of iris, retinal pigment epithelium (RPE), and choroid results in severe photosensitivity and low visual acuity. There are currently no FDA-approved pigment restoring therapies for OCA1, making therapeutic development an unmet clinical need. To address this gap, we have advanced an adeno-associated viral (AAV)-mediated Tyr replacement approach for OCA1 ocular pigment restoration. We evaluated the optimal viral delivery strategy and vector cell-type specificity for iris, RPE, and choroid pigmentation in an OCA1 mouse model, testing intraocular and systemic viral delivery methods in conjunction with viral constructs of varying RPE-specificity. Early, systemic delivery of an RPE-directed AAV-Tyr construct, AAV9.2yf-VMD2-Tyr, achieved widespread ocular pigment rescue with minimal off-target expression in non-ocular tissues. Animals treated with AAV9.2yf-VMD2-Tyr demonstrated reduced photophobic behavior compared to untreated controls, indicating that ocular pigmentation restores a debilitating functional consequence of OCA1. Our findings establish a foundation for clinical translation of an AAV-TYR therapy aimed at improving light sensitivity, glare, and low vision through pigment restoration in patients with OCA1.

Kindlin-1, encoded by FERMT1, is an essential integrin co-activator that regulates cell-extracellular matrix (ECM) adhesion, tissue architecture, and microenvironment signalling. Loss-of-function mutations in FERMT1 cause Kindler epidermolysis bullosa, which is strongly associated with aggressive cutaneous squamous cell carcinoma (cSCC). Although Kindlin-1 deficiency promotes hypoxia and invasion, the impacts on ECM-vascular organisation and oxygen homeostasis are not known. Here, using genetic deletion of Kindlin-1 in a murine model of cSCC across 2D cultures, 3D spheroids, and in vivo tumours, combined with collagen and vascular imaging and spatial mixed-effects modelling, we show that Kindlin-1 loss uncouples ECM-vascular regulation, driving hypoxia and tumour progression. Tumours in which Kindlin-1 was deleted displayed a dense but dysfunctional vascular network, with reduced tissue-to-vessel and inter-bifurcation distances, increased vessel alignment, and persistent hypoxia despite increased vascular density. Collagen deposition was reduced and fibres were straighter, indicating a simplified, invasion-permissive matrix. Hypoxia increased Vegfa and Angpt1 expression while reducing Col1a1, and hypoxia-responsive spheroids confirmed greater hypoxia and invasiveness in Kindlin-1-deficient cells. Transcriptomic analysis revealed enrichment of ECM degradation and vascular dysfunction pathways, including upregulation of matrix-remodelling and vascular permeability genes such as Mmp13, Mmp3, and Ptgs2, alongside reduced collagen-associated and vascular homeostasis genes. Spatial modelling further showed disrupted collagen-vascular coupling and an association between hypoxia and reduced vessel diameter, consistent with dysfunctional angiogenesis rather than improved perfusion. These changes arose early and independently of tumour size, establishing impaired integrin activation as a central mechanism linking ECM degradation, vascular dysfunction, and sustained hypoxia in aggressive cSCC.

The aim of this study was to explore the scalp bacterial flora structure and functional characteristics in androgenetic alopecia (AGA) patients, analyze its association with disease phenotypes and unhealthy lifestyles, and provide a basis for clarifying AGAs microecological pathogenic mechanism and targeted interventions. A total of 7 AGA patients and 6 healthy controls (HC) were enrolled, with scalp microbial samples collected. High-throughput sequencing of the 16S rRNA V3-V4 region was used to analyze flora alpha/beta diversity, species composition and differential species. LEfSe and KEGG functional prediction screened marker bacteria and differential pathways, and clinical/lifestyle data were collected for inter-group comparisons. No significant difference in Chao index was observed between groups (P>0.05), but Shannon/Simpson indices/Pielou evenness (P<0.01) and intra-group Bray-Curtis distance (P<0.001) were significantly higher in the AGA group, indicating reduced community stability. Staphylococcus dominated healthy scalps; the AGA group had fewer symbiotic bacteria but enriched Acinetobacter, Pseudomonas, andCutibacterium. LEfSe identified Firmicutes/Staphylococcus as HC markers and Proteobacteria/Gammaproteobacteria/Acinetobacter/Pseudomonas as AGA dysbiotic flora. KEGG showed upregulated metabolic, immune and cell motility pathways in AGA (P<0.05), with only infectious diseases pathway enriched in HC. AGA patients had more frequent hair washing and higher rates of staying up late, high-fat diet and insufficient fruits/vegetables (all P<0.05). In conclusion, AGA patients have typical scalp microecological dysbiosis closely related to unhealthy lifestyles, which may accelerate alopecia by inducing follicular inflammation. Scalp flora can be potential biomarkers and targets for AGA assessment and intervention.

Accurate risk stratification of pigmented skin lesions is critical for early melanoma detection and for reducing unnecessary excisions. Artificial intelligence (AI) is increasingly applied to dermoscopic image analysis, but its diagnostic performance relative to standard dermoscopy in real-world clinical settings remains uncertain. To address this gap, we conducted a systematic review and meta-analysis of prospective clinical studies directly comparing AI alone, dermoscopy, and AI-assisted clinicians for malignancy risk assessment of pigmented skin lesions. We systematically searched PubMed, Embase, Web of Science, and Cochrane Library from inception to January 2026. Ten studies with 17 diagnostic arms (10 dermoscopy arms, 6 AI-alone arms, and 1 AI-assisted clinician arm) were included. Pooled sensitivity and specificity were 0.773 (95% CI, 0.648-0.863) and 0.793 (95% CI, 0.673-0.877) for dermoscopy, and 0.757 (95% CI, 0.428-0.928) and 0.859 (95% CI, 0.619-0.958) for standalone AI. Summary ROC curves showed overlapping performance, indicating that autonomous AI is broadly comparable to dermoscopy but does not demonstrate a consistent advantage. Heterogeneity in AI performance was driven almost entirely by threshold effects rather than by differences in inherent model capacity. AI-assisted clinicians showed promising results (sensitivity 1.000, specificity 0.837) in a single study, but more evidence is needed. Our findings suggest that, at present, AI should be viewed as a complementary decision-support tool rather than a replacement for dermoscopic evaluation. The study provides valuable evidence for clinicians, guideline developers, and researchers working on AI integration into melanoma diagnostic pathways.

ImportanceAge-related eye diseases, such as cataract, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR), are leading causes of irreversible vision loss globally. Chronic inflammation is a shared pathogenic pathway, but the role of systemic inflammatory drivers like clonal hematopoiesis of indeterminate potential (CHIP) is unknown. ObjectiveTo investigate the association of CHIP, including its major genetic subtypes and clone sizes, with the risk of four major age-related eye diseases. Design, Setting, and ParticipantsThis was a prospective cohort study conducted using data from the UK Biobank, a large-scale, population-based cohort. A total of 436,469 participants free of the four eye diseases at baseline were included in the analysis. Data were collected from 2006 to 2010, with follow-up extending to March 2022. ExposuresCHIP status was ascertained from whole-exome sequencing data, defined by the presence of a somatic driver mutation with a variant allele fraction of 2% or greater. Main Outcomes and MeasuresThe primary outcomes were incident cases of cataract, glaucoma, AMD, and DR, identified through linked electronic health records. Associations were assessed using multivariable Cox proportional hazards regression models. ResultsOf 436,469 participants (mean [SD] age, 56.4 [8.1] years; 54.5% women), 14,110 (3.2%) had CHIP. Over a median follow-up of 13.1 years, CHIP was significantly associated with an increased risk of incident cataract (Hazard Ratio [HR], 1.08; 95% CI, 1.03-1.14), AMD (HR, 1.12; 95% CI, 1.04-1.21), and DR (HR, 1.41; 95% CI, 1.20-1.64). No significant association was found with glaucoma (HR, 1.08; 95% CI, 0.99-1.17). The risk for AMD was primarily associated with smaller clones (VAF <10%), while the risk for DR was highest with non-DNMT3A mutations. Systemic inflammation, particularly neutrophil count, partially mediated the associations. Conclusions and RelevanceIn this study, CHIP was independently associated with a higher risk of developing cataract, AMD, and DR, but not glaucoma. These findings establish a link between hematopoietic somatic mutations and the pathogenesis of several major age-related eye diseases, suggesting that CHIP-driven inflammation is a potential target for risk stratification and prevention. Key PointsO_ST_ABSQuestionC_ST_ABSIs clonal hematopoiesis of indeterminate potential (CHIP) associated with the risk of major age-related eye diseases? FindingsIn this cohort study of 436,469 participants, CHIP was associated with an increased risk of incident cataract (HR, 1.08; 95% CI, 1.03-1.14), age-related macular degeneration (HR, 1.12; 95% CI, 1.04-1.21), and diabetic retinopathy (HR, 1.41; 95% CI, 1.20-1.64), but not glaucoma. MeaningThese findings identify CHIP as an independent, non-ocular risk factor for cataract, AMD, and diabetic retinopathy, suggesting that systemic inflammation driven by CHIP contributes to the pathogenesis of these conditions and may represent a novel target for preventive strategies.