Allergy Tests

Risks

Skin tests

The major risk with the skin prick test or the intradermal skin test is a severe allergic reaction called anaphylaxis. Symptoms of a severe allergic reaction include itching, wheezing, swelling of the face or entire body, difficulty breathing, and low blood pressure that can lead to shock. An anaphylactic reaction can be life-threatening and is a medical emergency. Emergency care is always needed for an anaphylactic reaction. But severe allergic reaction is rare, especially with the skin prick test.

If you are having a skin patch test and you have severe itching or pain under any of the patches, remove the patches and call your health professional.

Blood test

There is very little risk of a problem from having blood drawn from a vein.

• You may develop a small bruise at the puncture site. You can reduce the risk of bruising by keeping pressure on the site for several minutes after the needle is withdrawn.
• In rare cases, the vein may become inflamed after the blood sample is taken. This condition is called phlebitis and is usually treated with a warm compress applied several times daily.
• Continued bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin) and other blood-thinning medicines can also make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your health professional before your blood is drawn.

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Author:	Debby Golonka, MPH	Last Updated: August 8, 2007
Medical Review:	Caroline S. Rhoads, MD - Internal Medicine Harold S. Nelson, MD - Allergy and Immunology
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