Allergic patients have an increased chance of getting allergic pneumonia, and there is no significant change in the chance of getting general pneumonia. Allergic pneumonia is a group of inflammatory diseases of the respiratory system induced by repeated exposure to organic and chemical antigenic substances. There are three main categories of antigens: first, microorganisms; second, proteins of animal origin, such as animal fur. Third, low-molecular chemicals, such as de-worming and pesticides. In fact, there are many manifestations of respiratory diseases caused by allergies, for example, in the nasal cavity mainly cause allergic rhinitis, manifested as runny nose and sneezing, if in the pharyngeal cavity mainly manifested as itchy throat and cough. If in the airway mainly manifest as cough, chest tightness, lung croup, if it is causing allergic pneumonia, on top of cough, chest tightness can also appear fever, chills, muscle aches and other symptoms.