An estimated one out of five Americans suffers from allergies. Determining the substance that is triggering symptoms (the \u201callergen\u201d) is the key to successful treatment. Allergy testing is the most effective method of accomplishing this. <\/p>\n
Skin testing is the preferred method because it is quick, inexpensive and reliable, but blood testing may be an alternative for patients who are unable to tolerate skin testing or those who are taking medications that might interfere with skin test results. <\/p>\n
The most common type of allergy test is the skin prick test<\/strong>. A drop of solution containing the suspected allergen is placed on the skin of the arm or back. Scratches or pricks are made with a needle or pin, allowing the allergen to penetrate the surface. Swelling or redness indicates an allergy to that substance. <\/p>\n In an intradermal dilutional test (IDT)<\/strong>, the allergen is injected beneath the skin with a syringe. The dosage is gradually increased until symptoms appear. Intradermal testing is extremely sensitive and is used for patients whose skin prick test results do not show an allergy is present, but that allergen is still believed to be the trigger. It is often used to test for a very specific allergen such as insect venom. <\/p>\n In a skin patch test<\/strong>, a patch that has been treated with drops containing the suspected allergen is taped to the skin and left in place for 24-72 hours. It is typically used to test for contact dermatitis. <\/p>\n Blood tests measure the levels of Immunoglobulin E (IgE) in the blood. This antibody attaches itself to a substance in order to trigger an allergic reaction. The most common blood test is a Radioallergosorbent (RAST)<\/strong> test. It screens for common allergy triggers such as pollen, mold, dust mites and pet dander. RAST is the preferred testing method for infants and children. <\/p>\n