目的　探讨咳嗽变异性哮喘(CVA)患儿支气管激发试验及小气道功能改变的特点。方法　选取2012年5月至2014年2月在三家医院门诊就诊的慢性咳嗽患儿353例，年龄(7.45±2.58)岁，分别进行常规通气肺功能检查、支气管激发试验及问卷调查，对比分析支气管激发试验阳性及阴性患儿肺功能的差异。结果　在353例慢性咳嗽患儿中，支气管激发试验阳性并符合CVA诊断的患儿200例(56.66%)。支气管激发试验阳性组患儿夜间咳嗽及剧烈干性咳嗽的比例明显高于阴性组，而晨起/日间咳嗽及湿性咳嗽的比例明显低于阴性组，差异均有统计学意义(P<0.01)。支气管激发试验阳性组患儿有特应性皮炎和鼻炎病史比例均高于阴性组，差异有统计学意义(P<0.01)。支气管激发试验阳性组反映小气道功能的FEF75(%)明显低于阴性组，差异有统计学意义(P=0.032)。结论　气道高反应性和小气道功能下降是CVA重要的病理特征，支气管激发试验及常规肺功能检测对CVA的诊断及慢性咳嗽病因的相关性分析具有重要的临床价值。

Objective　To investigate bronchial provocation test (BPT) and small airway function in children with cough variant asthma (CVA). Methods　A 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. Results　In 353 children with chronic cough, there were 200 children (56.66%) diagnosed as CVA with positive BPT. Compared with BPT negative group, the percentages of nighttime cough and severe dry cough in BPT positive group were significantly higher while the percentages of morning/daytime cough and wet cough were significantly lower (P<0.01). Furthermore, the rates of history of atopic dermatitis and rhinitis in BPT positive group were significantly higher than those in BPT negative group (P<0.01). Forced expiratory flow at 75% reflecting the small airway function was significantly lower in BPT positive group than that in BPT negative group (P=0.032). Conclusions　Bronchial hyperresponsiveness and decreased small airway function are the important pathological features of CVA. BPT and spirometry have clinical significances in the CVA diagnosis and the analysis of cause of chronic cough.