Allergy Tests and Asthma

Allergy tests for asthma can help get to the bottom of what's triggering your asthma symptoms. Allergy tests may help your doctor find your asthma triggers and prescribe the best asthma treatment to prevent breathing problems. While allergy tests alone are not sufficient to make an asthma diagnosis, when the test results are combined with your personal history of reactivity to an allergen, your doctor will have a better idea if the suspected allergen is causing your allergic asthma.

There are several types of allergy tests that might help with asthma, including allergy skin tests, allergy blood tests, and other diagnostic lab tests to determine if allergic disease is present. These allergy tests may also determine if you have an infection or if there is another problem. After performing allergy tests, your doctor may know what's triggering your asthma and allergy symptoms, and be able to treat these symptoms more effectively.

Allergy Skin Tests

Allergy skin tests are quick, fairly reliable, cost-effective, and may help your doctor determine your cause of asthma. Your doctor will have allergy test results usually within an hour of skin testing. It's important to ask your doctor for allergy skin test instructions. Antihistamines must be discontinued prior to an allergy skin test. Your doctor may have other specific instructions, too, which can make a difference in the allergy test results.

Skin testing is suggested if there is a reasonable suspicion that a specific allergen or group of allergens is causing your asthma and allergy symptoms. Skin tests involve injecting specific allergens under the skin to detect immunoglobulin E (IgE) mediated responses. This chemical, which is only found in people with allergies, activates mast cells in the skin. The mast cells then release chemicals called mediators, such as histamine, the chemical that triggers swelling, redness, and itching. A high level of IgE can show if an allergy is present.

Your doctor may use one or more of the following skin tests: prick, intradermal, or patch.

Warning: If you have poorly controlled asthma, reduced lung function, or are at a high risk for anaphylactic reaction to allergens, let your doctor know immediately as he or she may want to wait to perform skin tests. 

Skin Prick Test

The skin prick test is the most common allergy skin test. Tiny drops of allergens are dropped on your skin, usually the back. A needle is then pricked through the skin into each extract.  Within a period of less than 15 minutes, a hive will appear at the specific site if you have IgE antibodies to the particular allergen. Your doctor may also want to confirm that you have an allergic response to the allergen from your patient history or do a challenge and see if symptoms develop upon exposure to the allergen.