D1.244 - Clinical heterogeneity of pediatric atopic dermatitis: latent class analysis

Atopic dermatitis (AD) is a heterogeneous chronic inflammatory skin disease, differing in age at onset, severity, and association with allergic sensitization and comorbidities. While longitudinal birth cohorts have identified distinct AD phenotypes, data from Central and Eastern Europe remain scarce.

In this stydu, an anonymous online questionnaires were completed by parents of children (<18 years) with physician-diagnosed atopic dermatitis in Poland. Collected data included demographics, environmental exposures, age at AD onset, disease severity assessed by proxy Patient-Oriented Eczema Measure (POEM), recent exacerbations, viral skin infections, allergic comorbidities, and self-reported food and aeroallergen sensitization. Children were stratified by age (<6 vs. ≥6 years). Latent class analysis (LCA) was performed separately in both age groups using onset age, current disease severity, recent exacerbations, viral skin infections, and sensitization type to identify distinct AD phenotypes.

A total of 435 children were included (mean age 3.9 years; 59.8% male). AD onset before 6 months occurred in 67.1% of participants. Older children (≥6 years) more frequently had asthma, allergic rhinitis, and exclusive aeroallergen sensitization, whereas younger children were more often sensitized to food allergens. In children <6 years, three phenotypes were identified: (1) early-onset, moderate-to-severe AD with co-sensitization (n=100), characterized by the highest burden of food allergy and atopic comorbidities; (2) early-onset, mild AD (n=195) predominantly associated with food sensitization or no sensitization; and (3) later-onset, mild AD (n=64) with predominant aeroallergen sensitization and higher prevalence of allergic rhinitis. In children ≥6 years, two phenotypes emerged: an early-onset co-sensitized phenotype (n=53) with high rates of food allergy and asthma, and a later-onset phenotype (n=23) dominated by aeroallergen sensitization.

Distinct and clinically relevant phenotypes of pediatric atopic dermatitis can be identified using a cross-sectional, questionnaire-based approach. The observed phenotypes closely mirror those described in longitudinal cohorts, underscoring the heterogeneity of AD and supporting the value of pragmatic, region-specific surveys to inform personalized care and future longitudinal research.