The first part of the test is a skin prick (also known as a scratch test) with antigen attached to it. The prick only reaches the top layer of the skin. It’s relatively painless. We label each test spot with the specific allergen that’s placed there.
If the area swells and becomes red, like a mosquito bite, the test for that allergen is positive. We can often know within 15-20 minutes what the allergy trigger is.
If needed, we then do a retest on anything that pops negative. We use intradermal injections with a small amount of antigen in them. We do this to confirm if it is truly a negative or if it was a positive.
We don’t do the whole test with the intradermals because if you do have severe allergies to something, it could put you at risk for a reaction. So, we do the prick test first to minimize the amount of intradermals. This reduces the risk for a reaction.
Not used as often is an allergy blood test. We draw blood and then send it to a lab to check for allergen specific antibodies in your blood. Since this can change day to day, an allergy blood test isn’t quite as thorough as the skin test. This is why we typically only offer allergy skin testing at Texas Sinus & Snoring.