A skin prick test, also called a puncture or scratch test, checks for immediate allergic reactions to as many as 40 different substances at once. This test is usually done to identify allergies to pollen, mold, pet dander, dust mites and foods. In adults, the test is usually done on the forearm. Children may be tested on the upper back.
Allergy skin tests aren’t painful. This type of testing uses needles (lancets) that barely penetrate the skin’s surface. You won’t bleed or feel more than mild, momentary discomfort.
After cleaning the test site with alcohol, the Doctor draws small marks on your skin and applies a drop of allergen extract next to each mark. She then uses a lancet to prick the extracts into the skin’s surface. A new lancet is used for each allergen.
About 15 minutes after the skin pricks, the Doctor observes your skin for signs of allergic reactions. If you are allergic to one of the substances tested, you’ll develop a raised, red, itchy bump (wheal) that may look like a mosquito bite. A Doctor will then measure the bump’s size.
After the Doctor records the results, she will clean your skin with alcohol to remove the marks.
The screening kit includes the following allergens:
- grass mix
- house dust mites 1 – Dermatophagoides pteronnysinus
- house dust mite 2 – Dermatophagoides farinae
In addition, allergic skin tests can be performed with food allergens, which makes them particularly useful in the youngest patients with suspected food allergies.
Make sure you do not take antihistamines for 3 days before the test because they can affect the results.