D1.466 - Atopic dermatitis increases the risk of chronic systemic diseases in children and adolescents: a nationwide nested case–control study

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease of childhood, affecting up to 20% of children worldwide. Beyond its cutaneous manifestations, AD has been linked to a wide range of comorbidities, suggesting that early-life AD may serve as a precursor to chronic diseases across multiple organ systems. We aimed to investigate whether AD is a risk factor for chronic systemic disease in Korean children and adolescents.

We conducted a nationwide nested case-control study using data from the Korean Health Insurance Review and Assessment Service, including a birth cohort of individuals born in 2002 and followed from January 2002 to December 2020. Cases were defined as subjects diagnosed with chronic systemic diseases based on International Classification of Diseases (ICD)-10 codes. Each case was matched with five controls by sex and income level. AD was identified using ICD-10 codes, and severe AD was defined as AD requiring systemic treatment or hospitalization. Conditional logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs).

Among 495,039 subjects born in 2002, 13,600 cases of chronic systemic diseases were identified. AD was significantly associated with an increased risk of chronic systemic diseases, including autoimmune, metabolic, and cardiovascular diseases, autoimmune diseases, eosinophilic esophagitis, inflammatory bowel disease, nephritic syndrome, and diabetes mellitus (OR: 1.181; 95% CI: 1.137-1.228). A severity-dependent relationship was observed, with severe AD showing a higher risk than mild-to-moderate AD (Severe AD vs no AD: OR 1.218, 95% CI 1.146-1.294; Mild to moderate AD vs no AD: OR 1.164, 95% CI 1.108-1.222).

This study demonstrated that AD, including its severe form, is associated with an increased risk of chronic systemic diseases in children and adolescents, supporting the concept of pediatric AD as a systemic inflammatory condition.