What it is

Immunotherapy or hypo sensitization or as they are commonly called allergy shots involves increasing doses of the very allergens to which you are allergic! Over time this allows the body to gradually build up tolerance to the allergen, so the immune system stops reacting to the harmless substance. This, in turn, prevents the release of histamine and other allergy-related substances. Each vaccine is custom-made for each patient to conain liquid extracts of the precise substances (for example, dust mites, pollens, animal dander) that your skin test were positive to. Usually shots are given weekly (sometimes more often). After about seven months the top concentration is reached and over the next few months the time interval is increased to once a month for three to five years. Improvement in allergy symptoms, infections, and asthma is usually apparent in three to six months. About 65% of patients experience good relief (and another 20% some relief) for many years after the injections have ended. Some individuals may need to resume therapy after stopping if their symptoms reappear, and a few may always need them.

Side Effects

Most people tolerate Immunotherapy very well, although some will develop moderate swelling and redness at the site of the injection either right away or later. Occasionally, people experience systemic reactions to the shots, with symptoms such as itchy eyes, sneezing, nasal drip, swelling of the throat, chest tightness, cough and dizziness. These types of reations occur in only one out of every 1,000 (or more) injections. To be safe, patients must remain in the doctor's office for 20 to 30 minutes after the shots are given to ensure that serious adverse effects, if they occur, will take place under medical supervision. There is an increased risk with immunotherapy for people who have coronary heart disease and are taking beta-blocker medications for it, those with severe atopic dermatitis or severe asthma, and those having increased allergy symptoms on the day of the immunotherapy shot, or if several shots were missed.

The Bottom Line on Immunotherapy

Although this is the best long term treatment for allergies, especially for those who don't wish to take lots of medications, or have side effects, or incomplete control, this is not a "quick fix". People with seasonal allergies only (during "hay fever" season for example) get better results with immunotherapy than those with perennial (year round) allergic rhinitis or asthma. If avoidance strategies and treatments with medicatins fail to sufficiently relieve allergy symptoms, immunotherapy is an appropriate additional treatment to consider.