Differential Impact of Allergen Sensitization on Asthma Development in High-Risk Japanese Infants with Atopic Dermatitis: The Possible Role of Peanut Sensitization

Introduction: The atopic march describes the progression from early eczema to food allergies and asthma. In Japan, early-onset atopic dermatitis (AD) is linked to allergic diseases, but the role of peanut sensitization-a known asthma risk factor in Western populations-remains uncertain because of its lower prevalence. This study aimed to evaluate whether peanut sensitization predicts asthma development in Japanese children with AD and to compare its predictive value with other common allergens. Methods: We conducted a retrospective cohort study of 203 children under age two with physician-diagnosed AD who underwent simultaneous measurement of specific immunoglobulin E to egg white, peanut, and house dust mite at a tertiary Allergy Center in Tokyo. Participants were followed until age six. Sensitization was categorized as none, mono (one allergen), or oligo (≥2 allergens). Associations with asthma development were evaluated using multivariate logistic regression and decision tree analysis. Results: Asthma developed in 32.0% of participants. Peanut sensitization was significantly more common in the asthma group (53.8% vs. 29.7%, p = 0.001), as were oligo-sensitization and allergic rhinitis. Decision tree analysis identified peanut sensitization as the most influential predictor, with an 83% asthma incidence among children with both peanut sensitization and rhinitis. Logistic regression confirmed peanut sensitization as an independent risk factor (adjusted odds ratio: 2.74, 95% confidence interval: 1.44-5.24). Conclusions: Peanut sensitization in infancy strongly predicts asthma in Japanese children with AD. Early allergen-specific sensitization profiling may help identify high-risk children and support targeted asthma prevention strategies.