Risk factors and temporal associations of progression of the atopic march in children with early-onset atopic dermatitis

Background: Risk factors and the temporal relationship between atopic dermatitis (AD) and atopic march remain understudied. Objective: Determine risk factors for atopic march in early-onset AD patients and the temporality between AD and atopic march. Methods: We used the MarketScan Research Database for our retrospective cohort analysis from 2010 to 2018, comparing infants diagnosed with AD before age 1 with controls without early-onset AD. Primary outcomes were hazard ratios (HRs) for the development of asthma, allergic rhinitis, and food allergy. Results: Compared to 55,174 controls, higher proportions of the 27,228 AD patients developed asthma (19.21% vs 8.65%, P < .001), allergic rhinitis (28.27% vs 12.62%, P < .001), food allergy (16.00% vs 2.27%, P < .001), and all atopic triad conditions (10.69% vs 0.71%, P < .001). Among AD patients, higher proportions developed the atopic triad if they were male (HR 1.66, 95% confidence interval [1.45-1.90]), had severe disease (HR 3.16, [2.77-3.60]), or had family atopy history (HR > 3.40, P < .001 for all comparisons). Among AD patients, 20.1% developed allergic rhinitis. Limitations: Our study was based on health care claims data. Conclusion: Early-onset AD is associated with higher rates of developing atopic march conditions compared to controls. Particular attention should be paid toward risk factors and atopic march screening in early-onset AD patients. ( J Am Acad Dermatol 2025;92:732-40.)