The first step in treating allergies is determining which substances are causing your symptoms. Allergy testing will help us pinpoint the trigger and come up with a solution. We offer a few different testing options involving either the skin or blood.
Skin testing is considered the most reliable of all allergy tests. It is the least expensive, and offers immediate results. The most common test is the skin prick test, in which the patient’s skin is pricked or scratched with a needle after a drop containing the suspected allergen is placed on the arm or back, allowing the solution to penetrate beneath the surface. Should redness or swelling result, the test is considered positive.
Intradermal testing is another type of skin test, in which the allergen solution is injected directly into the skin with a hypodermic syringe. This type of test is extremely sensitive, and can be used to test for very specific allergies. Intradermal testing may be ordered when the results of a skin prick test were inconclusive or came back negative, but that allergen is still considered the trigger.
Some patients are unable to tolerate skin testing. Allergy blood tests can often be substituted. The most common type of blood test is the radioallergosorbent (or RAST) test. This is used to measure the levels of antibodies in the bloodstream. It is less sensitive than skin testing and results are less immediate, but it offers a good option for certain patients.
Your allergist will determine which type of test is right for you based on the severity of your allergies and any preexisting medical conditions that might affect the reliability of one type of test versus another.