What is allergen immunotherapy (also known as desensitisation)?

Allergen Immunotherapy (AIT), also known as desensitisation, is an allergy treatment designed to treat the underlying cause of the disease and which can have a long-lasting effect on all symptoms. After an accurate diagnosis of the type of allergy and responsible allergens, patients receive a targeted treatment, available in sublingual (tablet or drop) or subcutaneous (injections) form, based on market availability.

AIT works by inducing tolerance to allergens (the substance that you are allergic to) by rebalancing the immune system. The treatment consists of gradually exposing the patient to increasing amounts of the triggering allergens over time followed by a maintenance phase until the immune system naturally builds tolerance to that allergen (source: www.mayoclinic.org/tests-procedures/allergy-shots/basics/definition/prc-20014493?_ga=1.39037098.824990247.1423337969. Last accessed June 30, 2020. The immune system builds this tolerance by changing the types and proportions of antibodies (immunoglobulins) and other proteins (interleukins) it produces when it is exposed to the allergen (source: Moingeon P, et al. Immune mechanisms of allergen-specific sublingual immunotherapy. Allergy 2006;61:151-65). This ‘rebalancing’ of the immune response ultimately reduces the symptoms you experience when you are exposed to the allergen in your environment – even after you stop taking AIT. Adequately rebalancing your immune system with AIT usually requires 3 to 5 years (or seasons, in the case of pollen allergies) of treatment.

AIT is the only allergy treatment that works by treating the root cause of the allergy, and may provide a fast onset of action (within a few weeks) and long-lasting improvement of all allergy symptoms. This is in contrast to the usual symptomatic medications (read more about symptomatic treatments) that are prescribed, such as antihistamines and corticosteroids, which only temporarily relieve some of your allergy symptoms.