The etiological mechanism of asthma in children is complex and has multiple causes, the most common and important of which is allergy, so most asthma is allergic asthma. In children diagnosed with asthma, further allergen testing should be performed to find out whether the child with asthma has allergies, that is, whether his asthma is allergic, to which allergens he is allergic, and the degree of his allergy. After the type and degree of allergens are clarified through allergen testing, measures can be taken to avoid exposure to allergens for the purpose of preventing asthma attacks. For example, mites are the most common allergens. By cleaning indoor hygiene and using anti-dust mite bedspreads, exposure to mites can be reduced and acute asthma attacks can be reduced; children with seasonal pollen allergy can avoid exposure to allergens or stay away from these allergens by wearing masks during pollen season. Some studies have shown that children with well-defined allergens can have fewer asthma attacks if they can avoid allergens altogether and do not use any medications. In addition, if a child with asthma has a moderate/severe allergy to an allergen, or is predominantly allergic to an allergen, desensitization to that allergen can be used as “allopathic treatment” to reduce the clinical symptoms caused by the allergy, or even to “cure” it. Therefore, allergen detection is essential for the management of asthma. Therefore, allergen detection is very important for the definite diagnosis and long-term prevention of asthma. Only when the nature of asthma and allergies are clearly defined can effective measures be taken to avoid exposure to allergens and to determine whether immunotherapy is possible.