Lower airway cough syndrome (UACS): Various rhinitis (allergic and non-allergic), sinusitis, chronic pharyngitis, chronic tonsillitis, nasal polyps, adenoid hypertrophy and other upper airway diseases can cause chronic cough, previously diagnosed as postnasal drainage syndrome (PNDs). The ACPP recommends the name upper airwaycough syndrome (UACS) instead of PNDs. The clinical features and diagnostic clues of UACS are: (1) Chronic cough with or without sputum, coughing in the (1) Chronic cough with or without sputum, cough that is worse in the morning or when the position is changed, often accompanied by nasal congestion, runny nose, dry throat with foreign body sensation, repeated clearing of the throat, mucus adhesion to the posterior pharyngeal wall, a few children complained of headache, dizziness, low fever, etc.; (2) Examination of the sinus area may have pressure pain, yellowish-white discharge from the opening of the sinus, obvious hyperplasia of the posterior pharyngeal wall follicles, cobblestone-like, sometimes visible mucus-like adhesion to the posterior pharyngeal wall; (3) Targeted treatment such as antihistamines and leukotriene receptor antagonists (3) targeted treatment such as antihistamines and leukotriene receptor antagonists, nasal glucocorticoids, etc. are effective; (4) sinusitis caused by sinus x-ray or CT film can be seen corresponding changes.