ABSTRACT
ObjectiveTo investigate bronchial provocation test (BPT) and small airway function in children with cough variant asthma (CVA).MethodsA total of 353 children with chronic cough whose mean age was (7.45±2.58) years from three hospitals of Pudong district were enrolled during May 2012 and February 2014. Conventional pulmonary function tests, BPT and questionnaire survey were performed and the difference in pulmonary function was analyzed between children with positive BPT and negative BPT.ResultsIn 353 children with chronic cough, there were 200 children (56.66%) diagnosed as CVA with posi-tive BPT. Compared with BPT negative group, the percentages of nighttime cough and severe dry cough in BPT positive group were signiifcantly higher while the percentages of morning/daytime cough and wet cough were signiifcantly lower (P<0.01). Fur-thermore, the rates of history of atopic dermatitis and rhinitis in BPT positive group were signiifcantly higher than those in BPT negative group (P<0.01). Forced expiratory lfow at 75% relfecting the small airway function was signiifcantly lower in BPT posi-tive group than that in BPT negative group (P=0.032).ConclusionsBronchial hyperresponsiveness and decreased small airway function are the important pathological features of CVA. BPT and spirometry have clinical signiifcances in the CVA diagnosis and the analysis of cause of chronic cough.