1, air pollution: air pollution is an important factor in causing allergic diseases such as asthma, and indoor pollution is one of the main reasons for the prevalence of allergic diseases today. 2, changes in dietary structure: children’s digestive organs are not fully developed, the intestinal wall permeability is too strong, the body intake of protein particles that are not easily digestible by infants and children, resulting in increased allergies. 3, exposure of young children: exposure to allergens inside and outside the home within 1 year of age, such as house dust mites, dust mites, pets, pollen, fungi, etc., can lead to the production of allergic antibodies immunoglobulin E (IgE). 4, parasitic and infectious disease reduction: IgE will be significantly elevated in parasites or certain bacterial or viral infections. A strong IgE system is used to defend against parasitic, bacterial or viral infections. Due to the great improvement of the living environment and the massive application of preventive medicine, which has changed the spectrum of diseases nowadays, the incidence of parasitic infections and certain infectious diseases has decreased even more significantly in cities, but the defense function of the IgE system is still there. This has led to excessive defense against environmental allergens such as pollen, mite animal dander, food and particles, imbalance in immune function, and a large number of allergic diseases. 5, drugs and chemicals: due to the rise in the type and dose of drugs, the increase in extra-gastrointestinal administration, repeated intermittent long-term treatment with special drugs, etc. has increased the probability of allergic reactions. In China, the long-term abuse of a large number of antibiotics, in addition to leading to a large number of drug-resistant strains, but also lead to dysbiosis in the intestinal tract, some anti-allergic effect of cytokines such as interferon to reduce the production, resulting in the body’s anti-allergic ability to decline. Chemicals are ubiquitous in our lives, detergents, cloth, cosmetics, pesticides, fertilizers, plastics, rubber, etc. Because they are inseparable from human beings, they are also one of the herbal causes of allergy.