Allergen immunotherapy, also known as desensitization or hypo-sensitization, is a medical treatment for environmental allergies, such as insect bites, and asthma. Immunotherapy involves exposing people to larger and larger amounts of allergen in an attempt to change the immune system's response. Meta-analyses have found that injections of allergens under the skin are effective in the treatment of allergic rhinitis in children and in asthma. The benefits may last for years after treatment is stopped. It is generally safe and effective for allergic rhinitis, allergic conjunctivitis, allergic forms of asthma, and stinging insects. The evidence also supports the use of sublingual immunotherapy against rhinitis and asthma, but it is less strong. In this form, the allergen is given under the tongue and people often prefer it to injections. Immunotherapy is not recommended as a stand-alone treatment for asthma.