Immunotherapy (also known as allergy shots) was first introduced to treat allergic rhinitis (nasal allergies or "hay fever") one hundred years ago. The concept stems from the idea that the immune system can be desensitized to the substances (pollens, animal dander, molds, etc) that cause allergic nasal, eye and asthma symptoms. Allergy shots can lead to long term symptom control and reduce medication needs and may prevent the development of new allergies and asthma. Allergy shots are appropriate for patients whose symptoms are not controlled with simple medications and avoidance measures or who want to reduce long term dependence on medications. Since allergy shots are the only treatment currently that actually changes the immune system, immunotherapy is the only treatment which can potentially "cure" allergies.
Treatment involves administering injections of the allergen or allergens which are thought to be the cause of the patient's symptoms. Evaluation by an allergist can help determine which allergens cause a particular patient's symptoms by obtaining a thorough history and performing simple skin or blood tests. Injections are administered in two phases: the build-up phase and the maintenance phase. The build up phase consists occurs when increasing amounts of allergen administered once or twice weekly until a target dose is achieved. This usually takes 4-6 months with a traditional schedule but can be accomplished more quickly through use of an accelerated desensitization schedule. The maintenance phase begins once the target dose is achieved. Once the target dose is achieved the interval between injections can be increased, usually to 2-4 weeks in between injections. Maintenance injections are usually given for 3-5 years to help achieve long term desensitization. About 50% of patients will have lasting control of their symptoms following just one treatment course. Other patients will have recurrence of their symptoms months to years after stopping injections.
Immunotherapy is safe but serious life-threatening allergic reactions to the shots do occur rarely. Because of that risk, shots must be administered in a health care facility under supervision of a physician or trained physician extender (nurse practitioner or physician's assistant) capable of recognizing and treating severe allergic reactions. Allergy shots are a well studied and effective treatment and as such are covered by most insurance.
By Dr. Lane with Allergy Partners