Understanding Atopic Dermatitis Across Ethnicities

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease affecting diverse populations worldwide, including those in Asia, Africa, and Latin America. Recent research has highlighted the heterogeneity of AD, influenced by multiple factors such as ethnic background. This has led to a growing body of clinical, genetic, epidemiological, and immunophenotypic evidence illustrating differences in AD among racial groups. Filaggrin (FLG) mutations, the strongest genetic risk factor for AD, are found in up to 50% of European and 27% of Asian AD patients, but are very rare in Africans. Th2 hyperactivation is a common feature across all ethnic groups, though the Asian endotype of AD is also marked by increased Th17-mediated signaling. In contrast, African Americans display a strong Th2/Th22 signature without Th1/Th17 skewing. The ethnic heterogeneity of AD has important therapeutic implications, as genetic predispositions may affect treatment responses. This suggests the need for tailored strategies that better target the dominant immunologic pathways in each ethnic subgroup. However, white patients with AD constitute the majority in clinical trials and real-world treatments, limiting data on safety and efficacy across different ethnicities. This review aims to describe the heterogeneity in AD pathophysiology across ethnicities and explore its potential therapeutic implications.