Do not take antihistamines for at least 72 hours prior to skin testing. Skin testing is frequently done on your first visit to the clinic.

Skin testing is a method of testing for allergic antibodies. Testing consists of introducing small amounts of suspected substances, or allergens, into the skin and noting the development of a reaction. A positive reaction is noted when the allergen placed on the skin causes swelling and redness.

The results are read 15 to 20 minutes after the application of the allergen. Interpretation of skin tests requires the allergist’s skill in matching the test results with the patient history of allergy-like symptoms. Just because a skin test with a particular substance is positive does not necessarily mean that substance is causing the symptoms.

• Prick Method:
  These tests are done on the surface of the skin. A tiny amount of allergen is lightly pricked into the skin.
  
• Intradermal Method:
  This method consists of injecting small amounts of allergen into the superficial layers of the skin. This test is slightly more sensitive than the prick method.

You will be skin tested to important local airborne allergens and possible some foods. These include trees, grasses, weeds, molds, dust mites, and danders and, if needed foods (milk, egg, pecan, peanut, and others).

The skin testing session usually takes ½ hour. The testing is usually performed on your arms or back. If you have a specific allergic sensitivity to one of the allergens, a red, raised, itchy area (caused by the release of histamine and other substances into the skin) will appear within 15-20 minutes. These positive reactions will gradually disappear over a period of 30 to 60 minutes, and typically, no treatment is necessary for this itchiness.

Occasionally local swelling at the test site will begin 4 to 8 hours after the skin tests are applied, particularly where the intradermal testing was performed. These reactions are not serious and will begin to disappear over the next week or so. They should be measured and reported to your physician at your next visit.

After skin testing, you will meet with your physician who will make further recommendations regarding your treatment. Identifying the allergy causing agent is the only the first step in helping you manage your allergy symptoms most effectively. Allergy tests provide concrete information. Once you know the specific allergens causing your symptoms, you can try to avoid exposure to the allergen, get specific medical treatment, and if necessary, consider specific vaccination with the allergen, or “allergy shots."