Allergy skin tests are used to identify the allergens that trigger a patient’s allergic reactions. There are three primary skin tests:

• Scratch or prick test. Tiny amounts of allergens are placed on the skin, and a series of tiny scratches or needle pricks force the allergens into the skin.
  
  
• Intradermal test. Tiny amounts of an allergen are injected just below the skin.
  
  
• Patch test. An absorbent pad is soaked in an allergen and taped onto the skin of the patient for 24 to 72 hours.

During each of these tests, one or more allergens are introduced to the patient’s skin. For prick, scratch or intradermal tests, the healthcare provider administering the test waits 10 to 30 minutes to see if a local wheal, or hive, develops. For a patch test, the patient will return after 24 to 72 hours to be examined for a reaction. If a positive skin reaction to that allergen is detected, an allergy is likely.

Allergy skin tests are safe, fast, accurate and relatively inexpensive. In most cases, they cause little pain or discomfort. After a patient’s allergy has been diagnosed, a physician will recommend a treatment plan to reduce or eliminate symptoms.