1, the historical origin of desensitization therapy: desensitization therapy has been applied in the clinic for nearly 100 years. In 1911, the famous American allergist L. Noon was inspired by the Indian’s consumption of lacquer leaves to treat lacquer allergy, and the first time he used a small amount of pollen extract injection to treat hay fever allergic rhinitis was successful, thus creating a precedent for desensitization therapy. 2, the principle of desensitization therapy: desensitization therapy has been applied for nearly 100 years, but its principle still has some yet to be explored. In recent years, with the development of immunology and molecular biology, the mechanism of desensitization therapy has been understood from the cellular and molecular level, and the two currently recognized points include: ① the production of closed antibody: desensitization therapy will enable the body to produce specific closed antibody sIgG4, which can fight with sIgE, when the allergen enters the organism, it can be competitive with the combination of allergens to prevent the allergen from combining with sIgE, and thus preventing the allergen from combining with sIgE. prevent the binding of allergens to sIgE, and prevent the occurrence of subsequent reactions. ②Regulate the balance of T cells: some studies show that prolonged desensitization treatment can change the balance of TH1/TH2/Treg cells in the body. Desensitization treatment can inhibit the proliferative response of TH2 cells and enhance the role of TH1 cells. After desensitization treatment, when contacted with allergens again, the body mainly produces TH1 cell reaction, TH2 cells are inhibited, sIgE production is reduced, so that the allergic body can be fundamentally corrected. Comparison between desensitization therapy and drug therapy: desensitization therapy (treating the root cause) drug therapy (treating the symptoms) Safety There has not been a case of anaphylactic shock death in the laboratory in the past 22 years, so desensitization therapy for allergic rhinitis is relatively safe Some drugs have cardiotoxicity, but there are many high-efficiency, low-toxicity drugs available side effects Biological therapy, except for the temporary local redness, swelling, itching and pain in the process of injection, as well as a slight systemic reaction, basically no side effects. Side effects are biological treatment, except for temporary local redness, swelling, itching and pain during injection and slight systemic reaction, basically no side effects Some drugs have different degrees of side effects, but there are constantly launching high-efficiency, low-side-effects drugs Efficacy 80-90% of the patients on desensitization is effective, but the effect of the treatment is relatively slow, the effect of the treatment is rapid, and the duration of the maintenance time is short. Mostly in about 1 day. Long-acting hormones can last about 1 month, but are not recommended for routine use Cost Cost is relatively high. But in the long run, compared with other treatments, there is a better cost-effective, high efficiency, low toxicity and side effects of the higher cost; low cost of the toxicity and side effects of the heavier treatment time Treatment time is long, and it is difficult for patients to adhere to the treatment. However, persistence in treatment can lead to more stable results. Symptoms may recur after stopping the medication. 4, desensitization treatment of the appropriate population: (1) inhalation allergen test was strong positive; (2) drug treatment is not effective; (3) children and adolescents with allergies is more appropriate than adults, because of its better efficacy and can prevent new allergies, as well as future aggravation of allergic diseases; (4) combined with asthma or tendency to asthma; (5) the symptoms of the onset of a heavy, unbearable long-term medication, and the symptoms of the onset of the disease, and the symptoms of the onset of the disease, and the symptoms of the disease. (5) People who have more severe symptoms and cannot tolerate the long-term treatment with medication and want to obtain a long-term stable effect. People for whom desensitization is not suitable or recommended: (1) People whose allergen tests indicate that they are not highly allergic; (2) People who are unable to ensure that desensitization can be carried out on time because of work or study; (3) People who have severe asthma attacks and should not start desensitization during the attack. Must wait until the symptoms can be controlled and relieved; (4) pregnant women should not start desensitization treatment, if the desensitization treatment in the first and the pregnancy after the pregnancy, after pregnancy can still continue to desensitization; (5) other inappropriate desensitization treatment. 5, the preparation of desensitization therapy: the preparation used for desensitization must undergo strict production process and quality control. A series of processes such as allergen extraction, purification, sterilization, quantification and so on must be strictly quality control, otherwise it may affect the therapeutic effect or even cause complications and serious side effects. Another very important aspect is the standardization of allergen preparations for desensitization therapy. The purpose of standardization is to minimize the qualitative and quantitative differences between different batches of desensitizing preparations. Because desensitization therapy involves the injection of desensitizing fluids in a sequential manner from low to high concentrations. If the composition and concentration of allergens fluctuate too much during the injection, the body’s immune system will be difficult to form a good and orderly response, which may directly affect the efficacy of desensitization therapy, or even serious local or systemic side effects. Adverse reactions and side effects of desensitization therapy: The adverse reactions and side effects of desensitization therapy are generally mild, mainly including: (1) local reactions: mainly for the injection of local erythema, swelling, papules, local itching, local pain, local hardness. The localization can be reduced and subsided after applying hot compresses, and it is generally not necessary to stop or adjust the injection volume. The higher the injection concentration level, the higher the dose, the more local reactions occur, which is related to the powerful stimulating effect of allergens. (2) Systemic reactions: mainly urticaria or generalized itching, rhinitis and asthma symptoms after injection. Mostly appeared in high concentration and high dose injection, the general symptoms are not too serious, adjust the injection dose and medication treatment after the symptoms can be controlled, does not affect the continuation of desensitization treatment. Individual patients in the desensitization treatment when the dose is not appropriate, may appear more severe asthma reaction, should promptly contact the specialist and the desensitization dose should be adjusted accordingly. Note: In some places, anaphylactic shock caused by desensitization therapy has been reported in early years, but the cause was analyzed to be mostly due to wrong dosage or improper injection site, and anaphylactic shock mainly appeared in patients with higher degree of allergy, and mostly occurred in asthmatic patients. Therefore, desensitization is best performed by properly trained healthcare professionals. For hypersensitivity and asthma patients, desensitization treatment, especially should pay attention to safety. 7, the role and efficacy of desensitization therapy: desensitization therapy can achieve the following objectives: (1) can reduce the symptoms of allergic rhinitis, asthma, etc.; (2) can reduce the incidence of new allergies; (3) reduce the incidence of patients with allergic rhinitis in the future to develop asthma. (4) The immediate efficacy is about 90%, and the long-term efficacy is about 75%. The guarantee of the efficacy of desensitization therapy mainly depends on the following aspects: correct diagnosis by doctors, correct choice of desensitization treatment plan, good desensitization preparation, correct and standardized operation, and cooperation of patients. Factors affecting the efficacy of treatment: inaccurate search for allergens, inaccurate diagnosis, irrational treatment plan, problematic desensitizing preparation, irregular operation, poor patient cooperation or interference from other systemic diseases of the patient, and so on.