Characteristics of Atopy and Pulmonary Functions According to the Wheezing Phenotype in Preschool Children

Song, Young Hwa; Kim, Byoung Ju; Kwon, Ji Won; Yu, Jinho; Hong, Soo Jong

Abstract

PURPOSE
The wheezing phenotype in early childhood is heterogeneous and does not always develop asthma. However, the severity of the disease associated with these phenotypes has not been extensively studied in Korean children.
METHODS
Two hundred seventy-two children with recurrent wheezing aged 3-6 yrears who visited the Childhood Asthma and Atopy Center in Asan Medical Center from January 1998 to August 2007 were enrolled and followed up prospectively. The patients were divided into 3 groups: early-onset persistent wheezers (E/P) with asthma, E/P wheezers without asthma and late-onset wheezers with asthma. We investigated asthma-related biomarkers, pulmonary function and methacholine challenge at the age of 7.
RESULTS
FEF(25-75%) in the E/P wheezers with asthma was significantly lower than that in the late-onset wheezers with asthma. However, there was no significant difference in FEF(25-75%) between the E/P wheezers with asthna and those without. The E/P wheezers with asthma and the late-onset wheezers with asthma demonstrated enhanced Bronchial Hyperrsponsiveness (BHR) compared with E/P wheezers without asthma. Dermatophagoides farinae (D.f) or Dermatophagoides pteronyssinus (D.p)-specific IgE and sum of specific IgE in the late-onset wheezers with asthma were significantly higher than in the E/P wheezers with or without asthma.
CONCLUSION
The E/P wheezers with asthma and late-onset wheezers with asthma were associated with high levels of atopy and BHR, even though the late-onset wheezers with asthma were more related to atopy. The E/P wheezers with asthma showed decreased pulmonary function. These findings suggest that the development of asthma in Korean preschool children may be strongly associated with atopy and that E/P wheezers with asthma may show airway remodeling even before the age of 7.