Background: Although atopic dermatitis (AD) is associated with certain
gene variants, the rapidly increasing incidence of AD suggests that
environmental factors contribute to disease development. In this study,
we investigated the association of AD incidence and phenotype with
antibiotic exposure within 6 months of age, considering the dose
administered and genetic risk. Methods: This study included 1,637
children from the COCOA birth cohort. Pediatric allergists assessed the
presence of AD at each visit and obtained information about antibiotic
exposure for more than 3 days. IL-13 (rs20541) polymorphism was
genotyped by the TaqMan method. We stratified the AD phenotypes into 4
groups and used multinomial logistic regression models for analysis.
Results: Antibiotic exposure within 6 months of age was found to
increase the risk of AD within 3 years of life (aOR=1.40, 95%, CI
1.09–1.81) in dose-dependent manner. Antibiotic exposure more than
twice increased the risk of the early-persistent AD phenotype (aOR=2.50,
95% CI 1.35–4.63). There was a weak interaction between genetic
polymorphisms and environmental factors on the development of AD (p for
interaction=0.06). Children with the IL-13 (rs20541) GA+ AA genotype
have a higher risk of the early-persistent AD phenotype when exposed to
antibiotics more than twice than those with the IL-13 (rs20541) GG
genotype and without exposure to antibiotics (aOR=4.73, 2.01–11.14).
Conclusion: Antibiotic exposure within 6 months was related to the
incidence of early-persistent AD and a dose-dependent increase in the
incidence of AD in childhood, whose effect was modified by the IL-13
(rs20541) genotype.