Bronchodilator Response and Its Relationship to Bronchial Hyperresponsiveness in Children with Allergic Rhinitis/Asthma

Suh, Dong In; Lee, Ju Kyung; Lee, Jin Hee; Koh, Young Yull

Abstract

PURPOSE
Bronchial impairment has been observed in patients with allergic rhinitis (AR) as well as asthma. Few reports exist on bronchodilator response (BDR) and its relationship with bronchial hyperresponsiveness (BHR) in children with AR.
METHODS
A total of 309 children (170 asthmatic children, 80 children with AR and 59 control subjects) were included. After conducting methacholine bronchial provocation and BDR tests, we compared the mean of BDR between the 3 groups and examined the relationships between BDR, prebronchodilator forced expiratory volume in 1 second (FEV(1)) and provocative concentration causing 20% fall in FEV(1) (PC(20)) in both AR and asthmatic patients.
RESULTS
Asthmatic children showed a higher mean BDR than those with AR or control subjects. There were significant relationships between BDR, PC(20) and prebronchodilator FEV1 in asthmatic children. Children with AR also showed a higher BDR than control subjects. Though AR children with elevated BDR had lower prebronchodilator FEV1, they showed no significant relationship between BDR and PC(20).
CONCLUSION
Children with AR as well as asthma demonstrated an elevated BDR as compared to control subjects. Though the relationship between BDR and BHR in AR subjects was not so remarkable as in asthmatic children, the elevated BDR was associated with the decreased airway caliber in AR patients. These results may reflect the lower airway impairment in children with AR, which suggests a close link between AR and asthma.