How to Get a Blood Allergy Test

A blood allergy test is used to determine if you are allergic to certain substances. When you are allergic to a substance, your immune system produces antibodies to fight off that substance. Those antibodies remain in the blood even after the substance is removed. A blood test tells a physician what type of antibodies your blood contains in order to provide information on what is causing your allergies.

Instructions

Difficulty: Moderately Easy

1. Get an allergist/immunologist. These doctors specialize in diagnosing and treating allergies. Your primary care physician can refer you to an allergy specialist.
2. Discuss your allergy symptoms with your doctor. Your symptoms will help the doctor determine which antibodies to look for in your blood test. Different symptoms are triggered by different allergens.
3. Talk to your doctor about doing a skin test. Skin allergy tests are the standard diagnostic tool for allergies because they are highly sensitive, inexpensive and produce quick results. If you have severe eczema, anaphylaxis (dangerous allergic reactions) or are taking necessary anti-histamines or antidepressants, however, a blood test is indicated.
4. Get your blood drawn and sent off to the lab.
5. Wait for the results. Unlike skin tests, it can take days to get the results of blood allergy tests.
6. Let your doctor interpret the results of the blood allergy tests. Blood tests can be tricky to understand because positive results do not always indicate a physical reaction and negative results do not always negate a physical reaction.
7. Talk to your doctor about how to treat the allergies your blood test reveals. Various allergy medications are available that target specific allergies or treat a broad spectrum of allergies. Sometimes avoiding the allergen causing the reaction is the best approach.

Tips & Warnings

• Different types of blood allergy tests are often combined to create a clearer picture of your allergies. Radioallergosorbent tests (RAST) and immunoassay capture tests are often used in conjunction with enzyme-linked immunosorbent assay tests and other blood tests.
• If you are unable to avoid the substances that cause your allergies and medication is ineffective, you might want to consider getting allergy injections to desensitize yourself to the allergen causing the problem. Your allergist/immunologist can provide you with more information if this is a possible solution for you.
• Where food allergies are concerned, blood allergy tests are usually the safest type of allergy testing. Food allergies can produce severe allergic reactions that can be dangerous and even life-threatening, so skin testing is not usually recommended.