Atopic Dermatitis in Early Childhood and Risk of Inflammatory Bowel Disease: A Scandinavian Birth Cohort Study

Abstract

ObjectiveTo examine the association between early-life atopic manifestations and later risk of inflammatory bowel disease (IBD), for which prospective data are scarce. Study designThe population-based All Babies in Southeast Sweden (ABIS) and Norwegian Mother, Father, and Child (MoBa) cohorts follow children from birth (ABIS 1997–1999; MoBa 2000–2009) to the end of 2021. Based on validated questionnaires, parents prospectively reported information on asthma, food-related allergic symptoms, atopic dermatitis, and allergic rhinitis by age 3. IBD was defined by ≥2 diagnostic records in the national health registries. Cox regression estimated hazard ratios adjusted (aHR) for parental IBD, atopy, education level, smoking habits, and national origin. Cohort-specific estimates were pooled using a random-effects model. ResultsWe compiled data on 83,311 children (ABIS, n=9,041; MoBa, n=74,270). In over 1,174,756 person-years of follow-up, 301 participants were diagnosed with IBD. Children with atopic dermatitis at age 3 had an increased risk of IBD (pooled aHR=1.46 [95% confidence interval [CI]=1.13-1.88]), Crohn’s disease (pooled aHR=1.53 [95%CI=1.04-2.26]), and ulcerative colitis (pooled aHR=1.78 [95%CI=1.15-2.75]). Conversely, any atopic manifestation by age 3 was not associated with IBD (pooled aHR=1.20 [95%CI=0.95-1.52]), nor were analyses specifically focused on early-life food-related allergic symptoms, asthma, and allergic rhinitis. ConclusionWhile atopic manifestations in early childhood were overall not associated with IBD, children with atopic dermatitis specifically were at increased risk of developing IBD, suggesting shared etiological traits; these findings might be useful in identifying at-risk individuals for IBD.