Allergen immunotherapy is a medical treatment designed to help people with allergies. It works by gradually exposing the immune system to small amounts of allergens, such as pollen or pet dander, over time. This process helps the body build tolerance, reducing allergy symptoms and improving quality of life. There are two main types of allergen immunotherapy: subcutaneous immunotherapy (SCIT), which involves regular injections, and sublingual immunotherapy (SLIT), which uses tablets or drops placed under the tongue. Both methods aim to retrain the immune system, making it less reactive to allergens like dust mites or bee stings.