Bulent Mamikoglu, M.D.
Last updated: December 12, 2015
In general practice almost two thirds of adults report partial or poor relief with pharmacotherapy (i.e. nasal sprays, pills) for allergic rhinitis. The next step is treating such patients is allergen specific immunotherapy. There are two methods are available: traditional subcutaneous allergy injections, the second is the sublingual application of the allergens. This paper will review the subcutaneous method. The sublingual method is reviewed here.
First one must determine what the patient is allergic to. At Chicago Dizziness and Hearing, allergy tests are performed either by the physician or under direct supervision. Tests includes tree, grass, weed pollens, molds, dust mite and animal danders. We also test common foods.
Allergy shots involve injecting a small amount of an allergen under the skin, typically once/week, with the goal of building up tolerance to the allergen, and long-term relief from allergy. There is typically a "build up" phase, lasting as long as a year, and a maintenance phase typically lasting from 3-5 years.
As can be seen above, symptoms are generally reduced after one year.
All allergy treatment protocols entail risk of reactions -- these can divided into local reactions, and severe reactions. Local reactions might include redness or swelling at the injection site, which can occur immediately or after several hours from the injection. These can be annoying, but are not dangerous.
Anaphylaxis is a very severe reaction including swelling in the throat, wheezing, a feeling of tightness in the chest, dizziness, and sometimes lowered blood pressure. These reactions usually occur within 30 minutes of the injection, and for this reason, patients are advised to remain in the office for 30 minutes after getting their allergy shot.
Hurst et al (1999) reviewed their results considering more than a million injections, and noted "major systemic reactions" after 0.005% of injections. There were no hospitalizations or deaths. Risk factors included being in the "buildup" phase of immunotherapy, active asthma, and first injection from a new treatment vial.
Lee and others (2014) reviewed quality metrics and reported anaphylaxis in 0.01% of their allergy clinic visits, amounting to 1 in every 10,000 injections/year. Injections are best done in a clinic setting that has the ability to handle adverse reactions -- including availability of epinephrine, equipment to assist with breathing, rapidly acting antihistamines, and a "crash cart" should resuscitation be needed.