大矢 幸弘

BACKGROUND: The Prevention of Allergy via Cutaneous Intervention (PACI) randomized controlled trial (RCT) demonstrated that early enhanced topical corticosteroid (TCS) therapy modestly reduced food allergy (FA) at 28 weeks of age. The present prospective follow-up study (PACI-ON) evaluated whether these effects persisted to age 3 years. METHODS: Participants were randomized in infancy to early enhanced (proactive) or early conventional (reactive) TCS treatment (1:1) for atopic dermatitis (AD) until 28 weeks. A total of 590 (91%) children who completed the PACI RCT were followed to age 3 years. During follow-up, no protocolized interventions were given; all participants received usual care. Main outcomes included physician-diagnosed FA, AD severity (EASI, POEM), sensitization profiles, allergic comorbidities, and growth parameters as safety outcomes. RESULTS: At age 3 years, the prevalence of any FA remained lower in the early enhanced group than in the conventional group (47.4% vs. 58.8%, p = 0.006), mainly driven by a reduced prevalence of raw egg allergy (30.4% vs. 40.5%, p = 0.013). No between-group differences were observed for wheeze, asthma, or rhinitis. Japanese cedar sensitization at age 2 was lower in the enhanced group (6.1% vs. 12.2%, p = 0.02 6) but not at age 3. AD control and quality of life were well maintained and similar across groups, with > 90% achieving mild or less disease. Early growth suppression at 1 year resolved by age 3. CONCLUSION: Early enhanced AD intervention was associated with a sustained modest reduction in its planned primary follow-up outcome of FA and safety (growth) up to age 3. Although most differences were small and may reflect early diagnosis and good overall management in both groups, the findings support early AD treatment as a potential strategy to modify allergic disease trajectories.

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.