How Doctors Test for Skin Allergies

If you suspect that you have an environmental allergy, your doctor may recommend a skin allergy test.

This type of test is also used as a food allergy test. A blood test is another method of determining whether or not you have a certain allergy.

Skin Allergy Symptoms

One of the symptoms that points to a skin allergy is if you experience itchy skin, rashes or hives after being exposed to something in the environment or to a specific food. If you currently have a skin condition, your doctor will perform a skin test only on a part of your body that is clear. Most doctors will not use this type of allergy testing if you currently have a skin problem that is a result of allergies.

The Skin Test

A skin allergy test involves having a tiny amount of allergen placed on your skin. A small prick then drives the food or environmental substance underneath your skin. The test may be done on your back or arm. It is possible to test for as many as 30 different allergens at one time by using this method.

It is also common for allergists to test whether patients have food allergies by using a skin test. It is used to test for peanut allergy as well as for allergies to wheat, eggs, fish and milk. The most common allergens that are tested during a skin test are for cat and dog dander, mold, grass and tree pollen.

After the allergens are placed under your skin, you will need to wait about 15 to 30 minutes in your doctor's office. This is partially precautionary because someone with a severe allergy will begin to have a reaction within minutes after the allergen is placed under their skin. If the reaction is serious, allergists are prepared to treat their patients immediately to avoid anaphylaxis. When reactions are normal, the doctor or nurse will record the size of a hive that forms. The size determines how severe your allergy to a substance is at this time. No reaction means that you are not allergic to a substance. A follow-up blood test may be completed if results are found positive.