Division of Allergy & Inflammation
The Division of Allergy and Inflammation, part of the Department of Medicine, offers exceptional patient care, research programs, and education and training opportunities.
Allergy Testing
Helping you identify allergy triggers
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Diagnosing Allergy and Inflammation Conditions
The providers at Beth Israel Deaconess Medical Center (BIDMC) can diagnose allergies with a physical exam, family and symptom history and allergy tests. Allergy tests can help identify if you are allergic and what you are allergic to. Once your provider identifies your allergies, they can recommend avoidance and treatment options to help you get relief.
Types of Allergy Tests
Blood Testing
An allergy blood test can help determine if you have allergies. There is some evidence that blood tests are not as sensitive as scratch skin tests in determining allergies. You may have a blood test if you have skin problems or if there is concern that you will have a severe reaction to a skin test. However, this is very rare. There are many types of blood tests that are used to detect allergies. The most common one is RAST testing.
Positive skin or RAST tests help narrow the list of suspected allergens. However, they often don’t directly identify the cause of symptoms. Your medical history helps determine which of the positive skin test results really contribute to your allergy symptoms. A challenge test may also be needed. If your allergic reactions haven't been severe, the provider might deliberately expose you to one or more substances that produced a positive skin or RAST test. This is particularly true of medical testing for food allergies and food sensitivity.
Intradermal Skin Testing
Intradermal skin testing is often used when scratch skin testing is negative but there is still a strong suspicion of allergy. However, it is not as reliable as scratch skin testing. A small amount of each thing you may be allergic to (allergen) is placed under the skin with a needle, usually on the arm. If you are allergic to an allergen, you will get a bump and redness where the needle went under the skin. After a short time, each skin test reaction is measured for swelling and redness. If there is a large enough skin reaction, you may be allergic to that allergen.
Antihistamines and other medicines, such as antidepressants and sleeping pills, can affect skin test results. Ask your health care provider what medicines to avoid before your skin tests.
Scratch Skin Testing
A reliable test for allergies is the scratch skin test. A small amount of each thing you may be allergic to (allergen) is placed on the skin. It is often placed on the forearms. The skin is then pricked. If you are allergic to an allergen, you will get a bump and redness where the skin is pricked. After a short time, each scratch test reaction is measured for swelling and redness. If there is a large enough skin reaction, it means you may be allergic to the allergen placed at that site. The results of your scratch skin test and your symptom history will help your doctor determine if you have an allergy.
Contact Dermatitis/Patch Testing Clinic
The Contact Dermatitis Clinic is a referral-based specialty clinic that performs customized extended patch testing. Patch tests are a non-invasive way to determine if you are allergic to items that may come in contact with your skin. A patch test is used to identify reactions to different kinds of allergens, including chemicals, fragrances and preservatives in commonly used personal care products and occupational exposure.
After medical testing for allergies, you will know if any allergens were identified. Your provider will share information about your specific allergies. You’ll also receive a personalized list of products that can be used safely. Most patients are referred to us by primary care physicians, allergists or dermatologists from within and outside the BIDMC network.
