Background: Allergic rhinitis (AR) is the most common allergic disease in children and is closely associated with asthma in the context of atopic march. The development process of AR in early childhood, however, is not well understood due to the absence of definitive diagnostic criteria. We prospectively investigated the process in regard to not only the nasal symptoms and sensitization, but also the nasal cytology, in relation to asthma in a high-risk cohort. Methods: Infants under 2 years of age with atopic dermatitis (AD) and/or food allergy (FA) without a diagnosis of asthma were recruited and followed prospectively for 2 years. The phenotype of perennial AR was classified based on the presence/absence of 1) persistent nasal symptoms, 2) nasal eosinophils and 3) HDM sensitization, the most common allergen for perennial AR in Japan. AR-like phenotypes were defined as positive for at least 2 of those 3 categories. Results: A total of 304 children were enrolled, and 242 subjects (80%) completed the 2-year observation. The prevalence of eosinophilia in nasal secretions increased from 18.5% to 69.9%, while HDM-specific IgE >0.35 kUA/L increased from 30.6% to 74.8%. AR-like phenotypes increased from 18.4% to 65.0%. The cumulative incidence of physician-diagnosed asthma during the 2-year follow-up was significantly higher in the subjects with an AR-like phenotype at 1 year than in those with a non-AR phenotypes. Conclusions: The prevalence of an HDM-related AR-like phenotype was markedly increased during infancy in high-risk infants with AD/FA and was associated with asthma.

Background: Safely liberalizing the diet to include an allergenic food may accelerate resolution of food allergy. The outcome of liberalization, however, varies among patients. Methods: We conducted a prospective observational study to identify factors associated with outcome for egg allergy 1 year after oral food challenge (OFC). We enrolled children < 72 months-old who had egg allergy and underwent OFC for determination of the safe intake quantity of egg allergen. At enrollment, each child’s clinical background was recorded. The Food Allergy Quality of Life Questionnaire–Parent Form (FAQLQ–PF) was administered to the caregivers to assess their children’s QoL. Dietary advice based on the OFC result was then provided to support safe consumption of eggs. At 1 year after OFC, the quantity of egg each child safely consumed in daily life was surveyed. We classified the egg allergy outcome as Outgrowing (Group O) if the quantity increased during the 1 year, or as Non-outgrowing (Group N) if it did not. Factors associated with the outcome were investigated by multivariate logistic regression analysis. Results: A total of 93 children were enrolled, and after 1 year 57 finished in Group O and 36 in Group N. The mean FAQLQ-PF score at baseline was significantly lower (i.e., better QoL) in group O than in group N. Multivariate logistic regression analysis identified comorbid asthma, comorbid atopic dermatitis and a poor QoL as factors predicting an unfavorable outcome. Conclusion: QoL may affect food allergy outcome. Intervention focusing on QoL may promote outgrowing food allergies.