Epidemiology of atopic dermatitis

Atopic dermatitis (AD) affects approximately 129 million people worldwide and is now recognized as a chronic, heterogeneous condition with substantial burden across the lifespan. Epidemiologic studies in the last decade have been instrumental in characterizing the natural history of AD, highlighting both persistence into adulthood and the diversity of disease trajectories across individuals. Longitudinal studies have enabled the identification of distinct disease patterns related to AD onset, activity, and severity, as well as allergic multimorbidity over time. Additionally, increasing recognition of adult-onset AD has expanded our understanding of AD epidemiology, and large population-based investigations have emphasized the burden of disease beyond childhood. Recent evidence indicates that older adults experience high prevalence and severity of disease, underscoring the need for better understanding and management of AD across all ages. Finally, epidemiologic studies continue to shed light on environmental influences in AD, including dietary intake, early-life antibiotic use, and climatic exposures, including pollutants, highlighting their role in disease risk and course.