Allergen immunotherapy: guidelines, update, and recommendations of the World Health Organization

Allergen immunotherapy (AIT) is the administration of increasing doses of an allergen vaccine to an allergic subject in order to reach a dose effective to improve symptoms associated with subsequent exposure to the causative allergen. This form of therapy is effective in the treatment of allergic rhinitis/conjunctivitis, allergic reactions to stinging insects, and allergic asthma. It is the only therapeutic modality that can affect the natural course of allergic diseases, and may prevent the development of asthma in patients with allergic rhinitis. AIT is indicated for patients with demonstrated specific IgE antibodies against clinically relevant allergens. The mixture of allergens to be utilized is based on the patient's history and skin and laboratory tests. The major risk of AIT is anaphylaxis. Such therapy is continued for three to five years, but the decision to discontinue it should be individualized. Interpretation of the history, physical findings, and skin and laboratory tests, the prescription and administration of allergen immunotherapy, its integration into the patient's treatment plan, and the decision to discontinue it require qualifying experience provided by specialist training in allergy and immunology.