Options for Allergy Testing
Skin vs. blood (RAST) tests
Think you have allergies? Is your doctor suggesting tests? It's helpful to know your options, says the American Academy of Allergy, Asthma and Immunology (AAAAI).
Standard medical allergy tests are one way that you can get information on what you are and are not allergic to. The two standard allergy tests are the skin-prick test and the blood (RAST) test.
In the case of the skin-prick test, a minute amount of allergen is introduced directly into the skin by making a small puncture. In most cases, if you are allergic to the substance, you will have a reaction at the site of the puncture within a few minutes.
The advantage of the skin test is that results are available very quickly. In most cases, you will have a good idea of what you are allergic to within 15 minutes of testing. However, if you are unsure what you are allergic to and the potential allergens are many, it can be a relatively unpleasant test.
Not up for a large series of skin pricks on your back or arms? Another testing option is the RAST (radioallergosorbent) test. The RAST test is normally used when the skin-prick test cannot be, such as for patients with eczema. Obviously, if there is already a problem with the skin, you don't want to injure it as well. RAST testing may also be more accurate in diagnosing food allergies.
If you are having the RAST test done, blood will be drawn and then tested for IgE antibodies to specific allergens. In this case, you have enough blood drawn to test for all suspected allergens, as opposed to having an individual puncture for each.
The disadvantage of the RAST test is cost; it is usually more expensive than skin tests. Also, the results are normally not available for a number of days as the laboratory completes the work.
The good news: Regardless of what kind of testing you get, once you know what you're allergic to, you can determine a treatment plan with your medical practitioner. Generally, good treatment will yield a big improvement in many aspects of day-to-day life, including better sleep, fewer nasal symptoms, easier exercise and better control of any existing skin problems.
March 23, 2007
New Release, American Academy of Allergy, Asthma and Immunology