Common chronic cough in children with allergy-related disorders are: 1. Post-infectious cough: Acute respiratory infections with cough symptoms lasting more than 4 weeks can be considered post-infectious cough, the mechanism of which may be infection-induced disruption of airway epithelial integrity and squamous metaplasia of ciliated columnar epithelial cells or persistent airway inflammation with temporary airway hyperresponsiveness. The clinical features and diagnostic clues for post-infectious cough are: a recent history of definite respiratory infection; an irritating dry cough or a small amount of white sputum; no abnormalities on chest radiographs; normal pulmonary ventilation; cough is usually self-limiting; and other causes of chronic cough are excluded. If the cough lasts longer than 8 weeks, other diagnoses should be considered. Post-infectious cough is effective against nebulized glucocorticoids. 2. Cough variant asthma: It is a common cause of chronic cough in children, especially in preschool and school-age children. Diagnostic criteria: persistent cough greater than 4 weeks, frequent attacks at night and early morning, exercise, cough aggravated by cold air, no clinical signs of infection or ineffective after longer antibiotic treatment; diagnostic treatment with bronchodilators can result in significant relief of cough symptoms; normal pulmonary ventilation function, bronchial excitation test suggesting airway hyperresponsiveness; history of allergic diseases including drug allergy and positive allergic disease A family history of allergic diseases including drug allergy and positive allergic diseases, and a positive allergen test may assist in the diagnosis; except for chronic cough caused by other diseases. Treatment of allergic cough variant asthma is the same as asthma treatment. 3. Upper airway cough syndrome: Various rhinitis including allergic rhinitis or non-allergic rhinitis, sinusitis, chronic pharyngitis, chronic tonsillitis, nasal polyps, adenoid hypertrophy and other upper airway diseases can cause chronic cough. Allergic rhinitis is the most common cause of allergic cough.