Carmen Paredes‐Suárez

Background: Dyshidrotic eczema (DE), also termed acute and recurrent vesicular dermatitis, is a vesicular clinical pattern of hand eczema (HE) with heterogeneous aetiologies. Objectives: To characterise the clinical‐allergological profile of patients with DE and to compare it with non‐DE HE subtypes. Methods: A multicentre, retrospective, observational study was conducted using data from the Spanish Contact Dermatitis Registry (2019–2024). Results: Of 4378 patients with HE, 559 were diagnosed with DE. A longer median disease duration (24 vs. 14 months) and more frequent palmoplantar involvement (16% vs. 7%) were observed in DE compared with non‐DE HE. At least one positive patch test was identified in 43% of DE versus 52% in non‐DE HE. Although overall sensitisation patterns were largely comparable, DE showed lower sensitisation rates to 2‐HEMA, carba mix and thiuram mix. Occupational factors were less frequently implicated in DE (9% vs. 29%) compared with non‐DE HE. Conclusions: Despite a high overall frequency of contact allergen sensitisation, the pattern of findings suggests that the dyshidrotic phenotype may follow a clinical course less dependent on external or occupational triggers, pointing towards a relatively greater contribution of endogenous factors compared with other HE subtypes.

Background: Current relevance of positive patch‐test reactions guides management in allergic contact dermatitis (ACD), yet its clinical predictors and the use of predictive models in clinical practice remain underused. Objectives: To identify demographic and clinical factors associated with current relevance in ACD and to develop overall and allergen‐specific predictive models. Methods: A multicentric REIDAC study included data from patch‐tested patients with the Spanish baseline series. Exposure history, anatomical sites, atopic status, and occupational data were recorded. Logistic regression (LR) models were trained and internally validated to predict current relevance overall and for top frequent allergens. Model discrimination was assessed with area under the receiver‐operating characteristic curve (AUC). Results: Among 17 005 patients, 4077 (24.0%) had at least one currently relevant reaction. The final overall LR model achieved an AUC for the validation sample of 0.679. Allergen‐specific AUC parameters (LR) varied among allergens but performed best for nickel (AUC = 0.770). The independent factors associated with current relevance were female gender, specific body sites (hand, neck, head, leg, feet) and two occupations (hairdresser and construction workers). The use of other models (LASSO, gradient boosting) revealed similar results. Conclusions: Prediction modelling may moderately predict current relevance in ACD and several clinical variables are associated with current relevance in ACD.

Advances in the understanding of atopic dermatitis (AD) pathogenesis have driven the development of innovative systemic therapies targeting key immunologic pathways. This systematic review summarizes current evidence on the impact of biologic agents, Janus kinase (JAK) inhibitors, and other emerging treatments on AD-related biomarkers and their correlation with clinical outcomes. A comprehensive literature search was conducted across PubMed, Embase, Scopus, and Web of Science for studies published between 2014 and 2024. Eighty studies met the inclusion criteria. Dupilumab was the most extensively investigated therapy, followed by tralokinumab, JAK inhibitors, and novel agents such as amlitelimab, stapokibart, and tezepelumab. Across drug classes, consistent reductions in CCL17/TARC, LDH, and total IgE levels were observed, generally paralleling clinical improvement in EASI and SCORAD scores. Transcriptomic and proteomic analyses revealed normalization of Th2/Th22 inflammatory signatures and restoration of barrier-related gene expression, while microbiome studies showed a reduction in Staphylococcus aureus colonization. Despite these advances, the heterogeneity of study designs and analytical techniques limits the comparability of results. CCL17 and LDH currently represent the most reliable biomarkers associated with disease severity and treatment response, although their limited specificity restricts clinical applicability. Future research should aim to validate integrated biomarker panels combining immunologic, transcriptomic, and microbiomic data to enable precision medicine approaches in atopic dermatitis management.