Allergy tests are now more convenient and accurate than ever. When combined with a detailed medical history, allergy testing can identify the specific things that trigger your allergic reactions.
Today, prick or puncture tests are commonly used by allergists as diagnostic tools.
These tests are not very invasive and, for most allergens, they tend to produce quick results. If the results of prick or puncture tests are negative, they may be followed by intradermal tests, which give allergists more details about what’s causing the underlying symptoms.
Here is how both types of tests are administered:
Prick/puncture A diluted allergen is applied with a prick or a puncture on the surface of the skin.
Intradermal Using a 26- to 30-gauge (very thin) needle, a diluted allergen is injected immediately below the skin surface.
After either type of test, the area of the skin is observed for about 15 minutes to see if a reaction develops. The “wheal”—a raised, red, itchy bump and surrounding “flare”—indicates the presence of the allergy antibody when the person is exposed to specific allergens. The larger the wheal and flare/the greater the sensitivity.
Although skin testing may seem simple, it must be carried out by trained practitioners with an understanding of the variables and risks of the testing procedure.
Skin or sometimes blood (RAST) tests are performed to confirm the specific allergens to which the person has antibodies.Immunotherapy is usually recommended only if the person seems to be selectively sensitive to several allergens.