Allergen immunotherapy (also termed hyposensitization therapy, immunologic desensitization, allergen-specific immunotherapy, or the lay term “allergy shots”) is a form of immunotherapy for allergic disorders in which the patient is vaccinated with increasingly larger doses of an allergen with the aim of inducing immunologic tolerance. Allergen specific immunotherapy is the only treatment strategy, which treats the underlying cause of the allergic disorder, rather than the symptoms that are produced. It is a highly cost-effective treatment strategy which results in an improved quality of life and a reduction in allergic- and allergen-related asthma, as well as a reduction in days off school/work.
Immunotherapy has been shown to produce long-term remission of allergic symptoms, reduce severity of associated asthma as well as reduce the chances of new sensitizations to allergens developing. This is achieved via immunotherapy’s ability to modulate or change the immune system’s response to allergens.
Allergen immunotherapy can be administered under the tongue (sublingually) or by injections under the skin (subcutaneous). Subcutaneous injection immunotherapy has been shown to be highly efficacious treatment for allergic disease, has been recognized to be effective and safe for decades, and is the more commonly used method to desensitize one to specific allergens. Sublingual immunotherapy is widely used in Europe, but has not yet had official FDA approval in the United States. Research
confirms it is effective, although not as effective as subcutaneous immunotherapy, and takes a longer time to be effective. While the risk of death from a severe allergic reaction (anaphylaxis) from subcuaneous allergy immunotherapy is extremely rare, occurring less than one time in 2.5 million injections, there has never been a death from sublingual immunotherapy. It is also useful in patients who have a fear of needles, or in the very young patient who requires allergy desensitization. If given for treatment, sublingual immunotherapy is not reimbursable by insurers, is considered “off label”, and must be paid for “out of pocket” by a patient, at least until it is formally recognized by the FDA and insurors in the future.
Allergy injections are started at very low doses, with initial doses being given usually once, but occasionally twice, a week. The dose is gradually increased on a regular basis, until a "maintenance" dose is reached. Once the maintenance dose is reached, the injections are administered less often, still on a regular basis. Maintenance injections are normally given every three weeks for a few years.