Comparison of Pulmonary Function between Patients with Typical Asthma and Cough Variant Asthma

Objective To investigate the guiding significance of pulmonary function for the diagnosis of cough variant asthma (CVA). Methods The pulmonary functions of 63 patients with typical asthma and 113 patients with chronic cough,including 57 patients with CVA and 56 patients with negative results of bronchial provocation test (control subjects),were analyzed retrospectively. Results The pulmonary functions of CVA patients and control subjects were normal. FEF25～75% after bronchial provocation test significantly decreased in CVA patients (P 0.01). Conclusion Bronchial hyperreactivity and abnormal small airway function are the common features in patients with CVA and typical asthma. Bronchial provocation test can help diagnose CVA.