Sublingual specific immunotherapy is a specific immunotherapy method administered through the oral mucosa and gradually achieving immune tolerance. In 1986, Scadding GK, Brostoff J were the first to report the successful use of sublingual immunotherapy in the treatment of allergic rhinitis in a randomized double-blind trial study. Indications For IgE-mediated type I allergic diseases, including rhinoconjunctivitis, asthma, hay fever, hymenopteran insect venom and other allergies. Main products and types of SLIT The main products of SLIT include house dust mite, dust mite, pollen (grass, wallflower, olive, ragweed) and cat dander vaccines in two dosage forms: tablets and drops. Currently, only one type of dust mite drops is available in China. Routine treatment is divided into a dose-escalation phase (the dose is gradually increased in 4-6 weeks) and a maintenance phase (maintenance after reaching the maximum dose). Its protein content is 1mg/ml, 10mg/ml, 100mg/ml, 333mg/ml, 1000mg/ml. daily incremental dose and weekly sequential incremental concentration. 333mg/ml is maintenance dose for children and 1000mg/ml is maintenance dose for adults. The clinical efficacy of SLIT in rhinitis and asthma is mostly achieved within 1-3 years of treatment, with a small proportion taking effect within 1 year; its efficacy is significantly dependent on the duration of treatment and allergen dose. The evidence for its clinical efficacy is classified as Ia for rhinitis and Ib for asthma. Safety of SLIT The oral mucosa contains a limited number of proinflammatory cells, so SLIT has a good safety profile. SLIT is well tolerated in both children and adults, and no anaphylaxis has occurred after 5 billion doses in humans. the effectiveness of SLIT is dose dependent, but high dose administration does not significantly increase the the frequency of systemic and local side effects.