Allergic asthma is a subtype of bronchial asthma. As the name suggests, allergic asthma refers to asthma symptoms that are related to contact with external allergens, such as dust, pollen, dust mites, pet dander, etc. When these substances are inhaled into the trachea, they can trigger asthma symptoms. Clinically, when testing which substances a patient is allergic to, it is called allergen testing. Common methods include blood tests and skin prick tests, which can be combined for comparison to identify the allergens.