Most associations of early life environmental exposures and genetic risk factors poorly differentiate between eczema phenotypes. The Generation R study


Background: Childhood eczema is variable in onset and persistence.
Objective: To identify eczema phenotypes during childhood, and their associations with early life environmental and genetic factors.
Methods: In this study among 5,297 children of a multi-ethnic population-based prospective cohort study, phenotypes based on parental-reported physician-diagnosed eczema from age 6 months until 10 years were identified using latent class growth analysis. Information on environmental factors was obtained by postal questionnaires. Four filaggrin mutations were genotyped and a risk score was calculated based on 30 genetic variants. Weighted adjusted multinomial models were used for association analyses.
Results: We identified five eczema phenotypes: never (76%), early (8%), mid- (6%) and late transient (8%), and persistent eczema (2%). Early transient and persistent eczema were most common in first born children, those with a parental history of eczema, allergy or asthma and those with persistent wheezing (odds ratio (95% confidence interval): range 1.37 (1.07, 1.74) and 3.38 (1.95, 5.85)). Early transient eczema was most common in males only (1.49 (1.18, 1.89). Children with late transient or persistent eczema were more often of Asian ethnicity (2.04 (1.14, 3.65) and 3.08 (1.34; 7.10), respectively). Children with early, late transient and persistent eczema more often had a filaggrin mutation or additional risk alleles (range 1.07 (1.02, 1.12) and 2.21 (1.39, 3.50)). Eczema phenotypes were not associated with maternal education, breastfeeding, day care attendance and pet exposure.
Conclusion: Five eczema phenotypes were identified in a multi-ethnic pediatric population with limited differences in risk profiles, except for sex and ethnicity.

British Journal of Dermatology, 2019, 181(6), 1190 – 1197