Before allergy tests of any kind are conducted you will be asked to provide a detailed medical history. The questions will ask about previous illnesses, your emotional condition, elements of your environment (home, work and social), your lifestyle, and eating habits among other topics.

Before a skin-based procedure you must no take antihistamines before you go in for the allergy test. The use of antihistamines will lead to false-negative results. Before your test your doctor will review your prescriptions and indicate which ones you should not take before your allergy test. Skin tests also cause mild discomfort and there may be some itching afterwards.

Why would I Need an Allergy Test?

Allergy testing is not just conducted to identify the presence of specific substances causing an adverse reaction in an individual. A group of symptoms may involve antibodies and histamine release but not be an allergy at all. Some food intolerances, conditions in which a specific food cannot be digested due to a lack of enzymes, mimic allergic reactions. Also, the use of some drugs - aspirin, for instance - cause allergy-like symptoms. The tests are important to figure out the real cause of the adverse reactions and to treat them accordingly.

Do Allergy Tests Give Rise To Further Complications?

There are some risks in agreeing to skin and allergy tests. Some especially sensitive individuals may experience life-threatening episodes of anaphylactic shock characterized by distressed, difficult breathing as well as confusion, rapid pulse, fainting, palpitations, nausea, nasal congestion, and cough. Some people who have gone through this experience describe the feeling that their throats are closing up and they are unable to breathe.

Also, be aware that only penicillin and closely related medications can be tested via the skin method. Attempting this same procedure with other drugs will not offer informative results and can be dangerous.

There are also tests being offered that have no proven scientific validity. One of these is cytotoxic testing in which foods are blended in a test tube with a blood sample so the white blood cells can be observed for changes. A second unproven method is “provocation and neutralization” in which the person receives an injection of a suspected allergen and then, if a reaction occurs, is given more of the substance to “neutralize” the reaction. For obvious reasons, this latter method can be quite dangerous.

What To Do After The Test?

Whether you’ve had mold allergy testing or food allergy testing, observe yourselves in the period after the test and report any abnormal reactions to your doctor. If you’ve had a skin test, don’t scratch! Allergy testing and treatment involves active participation by the patient. The more your doctor knows about how you react to substances in real life the better that information with your allergy test will lead to successful treatment.

An allergy is an immune system malfunction that causes the body to have a hypersensitive reaction to a normally benign substance.

An allergy test of one form or another is often needed to determine which substance is causing the adverse reaction, especially if the problem seems to be originating from a food allergy. Testing may reveal that the individual is not allergic to the suspect food but rather to an ingredient in the food. Peanut oil, for instance, is a common culprit.

Although there are many allergy testing methods used to determine the presence of allergens, but the three most common allergy testing procedures are skin tests, elimination tests, and the radioallergosorbent test (RAST). It should be noted, however, that the accuracy of these tests varies widely and even the same test performed at different times may yield different results. It is also possible for a person to react to a substance during testing but not under normal exposure. False negatives occur often.

SKIN TESTS

Allergy skin testing is by far the most used of the three methods but it too varies in methodology. With the scratch test a small amount of the suspected allergen is placed on the forearm or upper arm (or on the back) and then introduced under the surface by scratching or pricking. The skin is then observed for swelling or redness. Results normally appear in about 20 minutes and the test can be conducted with a number of suspected allergens at one time. Skin tests are useful in detecting respiratory allergies, penicillin allergy, insect allergies, and food based allergies.

ELIMINATION TESTS

Food allergies are also often investigated via an elimination diet. Suspect foods are removed from the diet for several weeks and then re-introduced one at a time with the person monitoring their reactions. Because some people become convinced that they are allergic to a given food, double blind tests are sometimes required in which suspect foods and harmless placebos are disguised and given to the patient.

RADIOALLERGOSORBENT TEST (RAST)

Food allergies can be extremely severe however and given the potential for a life-threatening reaction, an allergy blood test is often a safer approach. The radioallergosorbent or RAST test is performed in a laboratory and tests for specific amounts of IgE antibodies that will be present in the blood during a true allergic reaction.