For most people, allergies are a minor nuisance. They come once or twice a year as hayfever, or cause sniffling when near dogs or cats. For some, allergies can be debilitating, making it virtually impossible to go outside or be in the same house as a family pet. In such cases, over-the-counter medication may not be enough to eliminate symptoms, and professional care from an allergist is necessary. Close scrutiny of allergy test results is conducted to determine a precise course of allergy shot treatment aimed at desensitizing and effectively curing a patient's allergies.
Desensitization treatment, known as immunotherapy, involves injecting increasingly large doses of allergen into a patient at a regular intervals. Over a period of a year or more, the patient grows increasingly less prone to allergic reactions from the specific substances. Immunotherapy is a targeted course of treatment, and the doses of serum are formulated to the specific sensitivities of a patient. Every patient is sensitive to different things to different degrees, so correct interpretation of allergy tests is critical in determining how to formulate the therapy.
Allergy tests are therefore the first step in immunotherapy. They involve small, subcutaneous pinpricks of very minute amounts of common allergens, including grass and tree pollen, dog and cat dander, mold, tobacco, dust mites, and cockroach droppings. The pinpricks are laid out in a grid fashion on a patient's arm or back, totaling roughly 30 different allergens.
The body reacts to the highly localized presence of the allergens by swelling up in small welts. Allergy test results are interpreted by judging the diameter of each welt after a period of around ten minutes. By comparing the diameters against a known metric, an allergist can calculate exactly how allergic the patient is to each substance.
Depending on how many different substances a patient is found to be sensitive to based on the interpretation of allergy test results, as many as three serums are created that must be injected on a weekly basis. This routine is maintained for a year, and then on a monthly basis for four years or more afterward. Roughly every four weeks or so, the serum is strengthened as part of the desensitization process. The increases in potency are calculated based on the initial allergy test results, so if an individual is highly allergic to grass pollen but not to dog dander, the amount of grass pollen in the serum will be much lower to start, while the dog dander will be present in greater quantities.