Atopic dermatitis (AD) has been extensively investigated for genetic associations utilizing both candidate gene approaches and genome-wide scans. Here, we comprehensively evaluated the available literature to determine the association of candidate genes in AD to gain additional insight into the etiopathogenesis of the disease. We systematically screened all studies that explored the association between polymorphisms and AD risks in cases of European and Asian ancestry and synthesized the available evidence through a random-effects meta-analysis. We identified 99 studies that met our inclusion/exclusion criteria that examined 17 candidate loci in Europeans and 14 candidate genes in Asians. We confirmed the significant associations between FLG variants in both European and Asian populations and AD risk, while synthesis of the available data revealed novel loci mapped to IL18 and TGFB1 genes in Europeans and IL12RB1 and MIF in Asians that have not yet been identified by genome-wide association studies. Our findings provide comprehensive evidence for AD risk loci in cases of both European and Asian ancestries, validating previous associations as well as revealing novel loci that could imply previously unexplored biological pathways.

Atopic dermatitis (AD) has been extensively investigated for genetic associations utilizing both candidate gene approaches and genome-wide scans. Here, we comprehensively evaluated the available literature to determine the association of candidate genes in AD to gain additional insight in the etiopathogenesis of the disease. We systematically screened all studies that explored the association between polymorphisms and AD risks in cases of European and Asian ancestry and synthesized the available evidence through random-effects meta-analysis. We identified 97 studies that met our inclusion/exclusion criteria that examined 17 candidate loci in Europeans and 14 candidate genes in Asians. We confirmed the significant associations between FLG variants in both European and Asian populations and AD risk, while additional synthesis of available data revealed novel loci mapped to IL18 and TGFB1 genes in Europeans and IL12RB1 and MIF in Asians, that have not yet been identified by genome-wide association studies. Our findings provide comprehensive evidence for AD risk loci in cases of both European and Asian ancestries, validating previous associations as well as revealing novel loci that could imply previously unexplored biological pathways.

Background/Objectives: We conducted the first pharmacogenetic investigation of atopic dermatitis in a cohort of 43 Greek patients, focusing on key variants within the IL6/JAK/STAT signaling axis, a pathway central to inflammation and therapeutic targeting. Methods: Patients receiving dupilumab, JAK inhibitors, or topical corticosteroids were prospectively evaluated, with treatment response assessed by changes in the Eczema Area and Severity Index over four months. Targeted genotyping of IL6R rs2228145 A>C, JAK1 rs2780815 T>G, and TRAF3 rs12147254 G>A were performed using PCR-RFLP. Results: Across the full cohort, no robust pharmacogenetic effects were detected, while baseline disease severity was the strongest predictor of absolute clinical improvement. However, stratified analyses revealed a significant association between the IL6R rs2228145 minor allele and reduced upadacitinib response (p-value = 0.026). Consistently, the same variant demonstrated a nominal association with reduced likelihood of achieving ≥75% improvement (p = 0.065). Conclusions: Although limited by sample size, these findings suggest potential treatment-specific pharmacogenetic effects within the IL6 pathway, supporting further investigation in larger cohorts to inform personalized therapeutic strategies in eczema.