Allergy Skin Testing

People with allergies make specific IgE-antibody proteins to allergens- substances, which cause allergy. The allergens could be pollen, animal dander, mold, food or medications. Allergy skin tests help us find out if you make IgE-antibody proteins specific for individual allergens. The tests are done by two methods: prick and intradermal. Each procedure takes about 30 minutes to complete. These techniques cause neither significant pain nor discomfort; they need not be avoided for this reason. In the prick method, your skin on the back or forearm is pricked with a plastic device whose tip is saturated with the test allergen. This causes a small break in the skin and introduces the allergen into the skin. In the presence of allergen specific IgE-antibody protein, a wheal and flare reaction takes place at the test site in 15-20 minutes. In general the larger the size of the wheal and flare the larger the amount of IgE-antibody present. The wheal and flare response is absent in the absence of antibody. Up to 70 allergens can be tested simultaneously in this manner on the back.

Unlike allergy blood tests, allergy skin tests are simple, safe and cost-effective way of finding out presence or absence of allergen specific IgE-antibodies. However the blood tests are preferable if you have extensive skin disease, are a woman and pregnant, have taken antihistamine medications within the last 3-10 days, or have had a previous acute allergic reaction to the test allergen.

It is important you inform your physician if this is the case. Then the physician will discuss with you the best way of evaluating your allergies. It is important you do not stop any medication for the purpose of skin testing without the knowledge of prescribing physician. Learn more about medications that could interfere with allergy tests.

One out of thousand skin tests may result in an acute allergic reaction known as anaphylaxis within two hours after the test. Click on the link to learn more about anaphylaxis. Sometimes the reactions could be delayed and protracted. Very rarely the reactions could end fatally. For this reason it is very important that you discuss with your physician about the risk versus benefit of undergoing allergy skin test and sign an informed consent. If you have any questions or concerns in this regard, please clarify with your physician before the test. You can feel confident in the knowledge that we have people and equipment available at our facility to take care of such reactions.

With the intradermal method, the allergens, which tested negative by prick method, are retested by injecting minute amounts into the skin using syringes and needles. Interpretation, risks and contraindications are similar to prick tests. In general, prick and intradermal tests are done on two different days to minimize the risk of allergic reactions and to minimize discomfort. We tend to avoid intradermal tests in small children (< 8 years) and in needle-shy individuals. However, bear in mind that without intradermal tests, allergies cannot be ruled out conclusively.

Most of the insurances cover the entire cost of these procedures. Some insurance may require prior authorization. Check with your insurance company for details. Call our office if you would like to schedule an appointment.