Risk factors, lung function and bronchial hyperresponsiveness in current dust mite-induced allergic rhinitis

Purpose: We analyzed the pulmonary function and risk factors of allergic rhinitis (AR) in dust mite-sensitized children with current AR and no history of asthma. Methods: In this cross-sectional study, demographic and disease-related information was obtained from 1,792 Korean children aged 9-12 years using a questionnaire, skin-prick testing, spirometric analysis, and methacholine challenge testing. Results: A total of 672 children were analyzed. The control group consisted of 583 children without any allergic diseases who were not sensitized to 16 common allergens. The group with current AR and dust mite sensitization consisted of 89 children. Binary logistic regression analysis showed that helminth infection (adjusted odds ratio [aOR], 2.88; 95% confidence interval [CI], 1.23-6.77) and antibiotic use during infancy (aOR, 1.89; 95% CI, 1.10-3.25) were the risk factors. Pet ownership (aOR, 0.32; 95% CI, 0.15-0.69) and older siblings (aOR, 0.58; 95% CI, 0.35-0.96) were protective factors. Spirometry results did not differ between the control and dust mite-induced AR groups. None of the children showed a bronchodilator response. However, 8.5%, 7.1%, and 2.1% of the control-group children and 28.7%, 23.0%, and 8.0% of the dust mite-induced AR-group children showed methacholine PC20 (provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second) values of <= 25 mg/mL, <= 16 mg/mL, and <= 8 mg/mL, respectively (P<0.01). Conclusion: The prevalence of current dust mite-induced AR may be reduced by controlling environmental factors. Even though the spirometry results seemed to be normal, bronchial hyperresponsiveness occurred more frequently in children with dust mite-induced AR than in normal children.