IgE is a type of human immunoglobulin, and there are five types of immunoglobulins in the human body, including IgA, IgE, IgD, IgG and IgM. Elevated IgE does not cause any disease, it is usually the manifestation of some diseases, the most common diseases that cause elevated IgE are allergic diseases, including allergic rhinitis, allergic conjunctivitis or allergic asthma, etc., all of which will show elevated serum IgE is elevated. Therefore, testing for IgE in the serum, combined with eosinophil testing and allergen testing, can help diagnose allergic diseases. Usually, IgE may decrease after anti-allergy treatment or desensitization therapy is given.