Allergic cough, also known as cough variant asthma, is a class of cough associated with exposure to allergens and is a common specific type of asthma. Its etiology may be due to allergic rhinitis leading to upper airway cough syndrome, allergic cough and other diseases. Allergic cough is usually a prolonged and persistent cough that lasts for at least 3 weeks. Allergic cough attacks are somewhat seasonal, usually with a high incidence in spring and autumn, and the cough tends to intensify at night or in the early morning. Patients develop an allergic cough when they inhale irritating odors such as formaldehyde, severe indoor air pollution, or when the air contains harmful gases. In addition allergic cough can also be caused after strenuous exercise or upper respiratory tract infection. The patient’s cough is mostly dry with little sputum, and if there is sputum, it is white and relatively small in volume. The cough is predominantly coughing and does not usually cause fever, often unconsciously rubbing the eyes and nose, scratching the scalp, sweating easily in bed, and writhing of the limbs or body. Some patients also have other allergic symptoms, and may experience allergic rhinitis symptoms such as nasal congestion, nasal itching and runny nose, or allergic conjunctivitis symptoms. Patients with allergic cough should be careful to find allergens and stay away from them to reduce the chances of developing allergic cough.