Diagnostic criteria for cough variant asthma: (1) cough lasting >4 weeks, often with episodes or exacerbations at night and/or early in the morning, with a predominantly dry cough; (2) no clinical signs of infection or ineffective with prolonged antibiotic therapy; (3) effective diagnostic treatment with anti-asthmatic drugs; (4) exclusion of other causes of chronic cough; (5) positive bronchial excitation test and/or PEF daily variability ( continuous monitoring for 1 to 2 weeks) ≥ 20%; (6) personal or first- or second-degree relative history of atopic disease, or positive allergen test. Items 1 to 4 are listed as basic diagnostic conditions.