The following special causes should be considered for long-term, untreated coughs in children: 1. Whooping cough, which is characterized by a paroxysmal, spasmodic cough that is lighter during the day and heavier at night, with a chicken-like retching sound after coughing. Mycoplasma infection can also cause a prolonged cough, mainly a dry cough, and requires a hospital test for mycoplasma to confirm the diagnosis. 3. 4. cough variant asthma, when the cough is not accompanied by fever, the use of general anti-inflammatory drugs is not effective, the cough will worsen after emotional excitement or activity, and anti-allergy treatment is effective, usually need to go to the hospital to check and exclude other diseases before diagnosis.