Cough variant asthma (CVA), also known as allergic cough, is one of the most common causes of chronic cough in children, with cough as the only or main manifestation, not accompanied by significant wheezing. Xing Xianghui, Department of Pediatrics, Affiliated Hospital of Shandong University of Traditional Chinese Medicine Diagnosis based on: 1. cough lasting >4 weeks, often occurring at night and/or early in the morning, aggravated by exercise, cold air or smell of a specific odor, little sputum, mainly dry cough; 2. no clinical signs of infection or ineffective after prolonged antibiotic treatment; 3. effective diagnostic treatment with anti-asthmatic drugs; 4. exclusion of other causes of chronic cough; 5. Positive bronchial excitation test and/or PEF (i.e. peak expiratory flow rate) daily variability (continuous monitoring for 1-2 weeks) ≥ 20%; 6. Personal or first- or second-degree relative history of atopic disease or positive allergen test. Items 1-4 above are the basic conditions for diagnosis.