Abstract
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.
(245 words)