Also referred to as immunotherapy, allergy shots are injections that are given over a period of time to help the body's immune system develop a tolerance for specific allergens. The shots themselves contain a very small amount of the allergen to help the body learn to adjust, reducing or even eliminating allergic reactions to that allergen. As time progresses, the amount of allergen in the injection solution will be gradually increased to help the body develop a tolerance.
Immunotherapy shots are typically administered once or more per week over several weeks to begin with. In most cases, the shots are given in the upper arm. During the first cycle which can last from three to six months, the focus will be on developing a tolerance for the allergens. Once a tolerance has been established, monthly maintenance shots will be administered over several years to help ensure the body remains resistant. Once a shot has been administered, you'll need to remain in the office for about a half hour to ensure an allergic reaction doesn't occur. Sometimes, the initial treatment cycle can be completed more quickly by increasing the dose with each injection; however, since this approach can also increase the likelihood of an allergic reaction, it's not an ideal approach for every patient. Once a shot has been administered, you'll need to remain in the office for about a half hour to ensure an allergic reaction doesn't occur.
In most cases, the effects of immunotherapy will be felt during the first year, with substantial improvement in symptoms during the second year. Depending on your response, you may need several years of maintenance therapy or you may not need any maintenance shots at all.