lgE is an immunoglobulin, an immune molecule that plays a major role in the pathogenesis of type I allergic reactions, such as allergic rhinitis, allergic asthma, atopic dermatitis, eczema, and acute and chronic urticaria, and is therefore the primary test in the immunological diagnosis of allergic reactions. lgE elevation can indicate a greater likelihood of type I allergic reactions, but it cannot be used to determine allergens. For high lgE, especially in small children, allergens such as bacteria, viruses, molds, meat, soy and also milk, which are contained in higher levels. Secondly, it is also necessary to pay attention to plasma cell diseases, such as multiple myeloma IgE type, often combined with anemia, bone destruction and kidney function damage and other manifestations.