There are two methods of allergy skin testing; prick testing and intradermal testing.  The type of allergy being evaluated, (pollens, foods, insect, etc.) will determine which type or combination of testing is done.  When indicated testing can be done on infants as early as twelve months age.
 
Allergy skin prick testing is a method to determine if you have sensitivity to specific allergens.  Small drops of purified allergen are applied to the skin (most often on the back) with a tiny plastic prick.  Application takes less than 5 minutes.  Sensitivity is indicated by an area of redness with a raised hive at the test site within 15 minutes.  This type of response suggests that the patient may be allergic to the particular antigen tested.  There is minimal discomfort during application and some itching may occur after the procedure.  This usually resolves within a couple hours or less.

Depending on the finding of the skin prick testing, your doctor may decide to do additional intradermal testing next.  In this test, the antigen is injected into the superficial layers of the skin, (like a TB test).  This testing is done on the upper arm.  After a period of 15 minutes the test sights are measured. 

All patients who plan to have allergy skin testing performed should not use any antihistamine medications (benadryl, claritin, allergra, zyrtec, atarax, etc.) for 7 to 10 days prior to testing as these medications may interfere with test results.  Certain antidepressants (tricyclic antidepressants) and acid blockers (pepcid, zantac, axid, etc.) should also be avoided 10 to 14 days prior to testing as these may also interfere with testing.  Contact the office in advance for a list of medications to avoid or to inquire about specific medications that you are taking.

The reactions that may result during allergy skin prick testing (redness, itching, or hives) usually resolve within a couple of hours or less and taking antihistamines after the test may be helpful for highly reactive patients. Occassionally, a "delayed reaction" may occur many hours after an initially negative test result with new onset of itching, wheals or redness. This late reaction does not represent an allergic reaction due to allergic antibodies and usually resolves on its own within minutes to a few hours.