There are two types of variant asthma, cough variant asthma and chest tightness variant asthma, whose clinical manifestations are cough variant asthma with cough as the only symptom and chest tightness variant asthma with chest tightness as the only symptom.
Cough variant asthma occurs when exposed to allergens or cold air, and is characterized by a cough as the only symptom, which often occurs at night and decreases during the day. Positive bronchial relief test or bronchial provocation test.
Chest tightness variant asthma can occur after exposure to allergens or strenuous exercise and is characterized by chest tightness as the only symptom, with frequent nighttime attacks. Positive bronchodilator test or bronchial provocation test.
Variant asthma is not characterized by the typical symptoms of asthma, such as dyspnea and shortness of breath, and therefore requires careful diagnosis.