Identifying an allergy is the first step towards managing or treating any allergy and to this end knowing about the correct allergy testing procedure is vital. We look at all the different options for allergy testing that can give accurate results as to the type and severity of allergy that a person has. The main allergytesting methods are skin tests, blood tests and elimination type tests.
Skin test is the most commonly used allergy testing procedure for detecting food allergies, animal, pollen, dust, mold, venom and drug allergies as well as contact dermatitis. Is may be done in one or more of the following manners-
1. The prick test uses skin pricks or scratches with needles to let suspected allergens enter into the skin’s surface.
Solutions containing the allergen that the person suspects they are allergic to are used to gauge the reaction of the substance.
A person is allergic to the substance that causes a wheal – a reaction such as redness, itchiness, rashes, etc.
2. Patch tests are administered to indentify cases of contact dermatitis and so on.
Here the allergen soaked pad is taped on to the person’s skin for one to three days to see if there is a reaction.
3. Sometimes the allergen may be injected into the surface of the skin if the prick test appears to have yielded incorrect results. However the intradermal allergy testing procedure as it is called can be overly sensitive and may yield a false positive result at times.
Blood tests for allergies require the blood to be tested for certain antibodies. They are used when a person is unable to take skin tests though they are less likely to yield accurate results. The enzyme-linked immunosorbent assay (ELISA, EIA) is the most frequently used blood test for detecting allergies. It measures the amount of antibodies present in the blood.
The RAST (radioallergosorbent testing) method of testing may be used for additional information. Other tests such as the one to test absolute eosinophil count or total IgE levels may be conducted.
Elimination type of allergy testing procedure is used mainly to detect food allergies. By turn certain suspected food allergens are eliminated from the diet of the person for a period of several weeks. The food is then once again introduced to the diet to see what reaction it has.
Provocation type testing may also be used to find out what one is allergic to. Here a person is exposed to different allergens and their reactions recorded in controlled conditions.
Double blind tests can also be performed where allergens as well as harmless substances are used; without the person knowing which is which. This allergy testing procedure has to be carefully controlled and can be used if the person’s allergic reactions are not known to be severe.
Whichever allergy testing procedure you are advised to undergo, you should known what each entails and should help by giving complete medical information about yourself and your suspected allergies to the doctors. Never take any allergy medications prior to a test.