Purpose: The effect of allergic rhinitis [AR] on pulmonary function and risk factors of AR are controversial. The purpose of this study was to analyse the risk factors and pulmonary function in dust mite sensitized, current AR children who were never diagnosed as having asthma.
Methods: A cross-sectional study of 1,792 children aged 9-12 years from Korea was conducted. Demographic and disease related information was obtained via a detailed questionnaire, skin prick test, pulmonary function test, and methacholine challenge test.
Results: A total of 672 children were included in the analysis. 583 children who were not sensitized to common 16 allergens and not having any allergic diseases were classified as the control group. 89 children were classified as the current AR with dust mite sensitization group. The binary logistic regression analysis evidenced that non-farming parents(adjusted odds ratio[aOR] 1.95, 95% CI 1.00-3.08 ), no older siblings(aOR 1.99, 95% CI 1.22-3.25), use of antibiotics during infancy(aOR 2.18, 95% CI 1.13-3.70), helminth infection(aOR 2.61, 95% CI 1.13-6.03), low income (aOR 0.33, 95% CI 0.12-0.92), and pet ownership(aOR 0.24, 95% CI 0.11-0.51) were risk or protective factors. There was no difference in spirometry between control and current AR groups. None of children showed bronchodilator response. However, methacholine PC20(provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second[FEV1]) less than 25, less than 16, less than 8mg/mL were 8.5%, 7.1%, 2.1% in control group and 28.7%, 23.0%, 8.0% respectively in allergic rhinitis group (p=0.00).
Conclusions: We might reduce the prevalence of dust mite sensitized current AR by controling some environmental factors. Even the spirometry seems to be normal, bronchial hyperresponsiveness occurs more frequently in children with dust mite sensitized AR than normal children.