What is AIT?

AIT is based on the principle of introducing allergens in small doses over a long period, to induce desensitization. Some conditions in which AIT is useful include allergic asthma, allergic rhinitis, allergic conjunctivitis and allergy to stinging insects.

The concept was first introduced in 1911 by Noon, an English physician, who gave patients with hay fever injections of timothy grass extract. This treatment was followed by remarkable increases in tolerance to the allergen at 100 times the original dose. This has evolved to modern immunotherapy via the use of standardized allergens and immunotherapy, as described by Robert Cooke in 1916.

The benefit of AIT is its long-lasting effect, which keeps the previously sensitized individual free of allergic symptoms over the long term. This is therefore a more cost-effective approach for many allergy sufferers than medical treatment.

Allergy shots are suitable for patients of all ages, though not usually given to children below 5 years who may not be able to communicate side effects they experience and are generally unwilling to receive repeated injections.

The greatest benefit is likely in those patients who experience prolonged periods of allergic symptoms each year, and those who have severe symptoms including anaphylactic reaction. Those who feel that their symptoms are not helped much by medical treatment and avoiding environmental triggers, and those who dislike being on medications for a long time may also be good candidates for AIT.