Desensitization therapy, which should be called immunotherapy to be exact, is a therapeutic measure that allows the patient’s immune system to gradually adapt to such allergens by injecting specially treated allergens so that no further allergic reactions occur when exposed to similar substances. Desensitization treatment can be done by both sublingual desensitization and intradermal injection. With both modalities, the treated allergen is allowed to enter the patient’s body, and the patient is gradually made tolerant to the stimulation of the allergen by successive injections or oral administration, from low to high doses. Usually after 3-6 months or even 1-2 years of desensitization treatment, the allergic reaction is diminished or disappears. Usually after desensitization treatment, patients have more satisfactory results and are not as prone to allergy after exposure to allergens as before and can return to normal life. The desensitization treatment modality is suitable for patients with allergic diseases, especially those who are allergic to one or one type of allergens alone, such as allergic asthma and atopic dermatitis, as well as those who have side effects from medication and those who do not want to receive long-term medication. However, there are contraindications associated with desensitization treatment, such as poor patient cooperation, or suffering from serious cardiovascular diseases, immune system diseases, cancer, or inability to identify the allergen.