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Allergen Intradermal Skin Test

What To Expect

This procedure is performed on the upper arm and is used ONLY FOR SUBLINGUAL IMMUNOTHERAPY PRESCRIPTIONS. It entails using common allergens and allergen mixes (these mixes are not used in prick testing) to determine problem allergens and dosing for Sublingual Immunotherapy. This test CANNOT BE USED FOR IMMUNOTHERAPY BY INJECTION.

The test is performed by cleansing the skin of the upper arm with alcohol, allowing it to dry, and is then marking the area with a pen for allergen placement. A tiny drop of allergen is then injected under the dermis of the skin with the thinnest and smallest of needles (similar to a beading needle). The needle is inserted ever so slightly under the skin at the time of injection so the tip is still visible while in the skin. Injecting the allergen intradermally creates a small bump similar to a mosquito bite which will either disappear without any further sequelae or become red and itchy with time. Those allergens which react are considered positive. Positive reactions indicate the presence of an allergy to this specific allergen.


The patient must not consume any antihistamines such as Allegra, Zyrtec, Benadryl, Clarinex, Claritin, Alavert, Xyzal or Cold preparations, nor any Antacid H2 blockers such as Zantac, Pepcid or Tagamet for at least 7 days prior to their skin test. CALL YOUR PHARMACIST TO CHECK ALL YOUR MEDICATIONS – PRESCRIBED AND OVER THE COUNTER they will be happy to check if a medication blocks an allergy skin testing.


The area may be very itchy if there is a positive reaction. After testing, we can apply a topical treatment to relieve the itching. We will ask the patient to read the test on their arm 24 hours and 48 hours after the test (similar to a TB Test). This is especially important for mold testing as molds are notorious for producing DELAYED REACTIONS.