Types of Allergy Testing

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Definition of An Allergy

An allergy is an abnormal reaction experienced by a person because his/her immune system views a normal substance as foreign and the body goes into defense mode. An individual without allergies would not have a reaction to the substance while an allergic individual individual may experience a full range of signs and symptoms based on the particular allergic condition.

For example, some common signs and symptoms demonstrated by a person with allergic rhinitis includes a runny nose, nasal congestion, and constant sneezing. A person with food allergies may experience gastrointestinal signs and symptoms such as stomach cramping with moderate diarrhea and mild nausea.

Skin Tests

A skin test involves applying a tiny amount of an allergen to a small area of the skin by puncturing, pricking, or administering a needle. Some common allergens testing are pollens, molds, and dust mites, and this test should be performed by a qualified allergist or under the supervision of an allergist if performed by a nurse or lab technician.

Before the skin test is performed, a patient should inform his/her allergist about any specific allergy medications so that the drugs can be discontinued before the skin test is performed. This lowers the risk of a false negative allergy skin test which will make an individual think he/she does not have a specific allergy when there actually is an allergy.

The allergy tester will inspect the skin for swelling and redness and consider this as possible evidence that an allergy exists. Depending on the skin test results, an allergist may establish a treatment plan such as avoiding the allergen.

Blood Tests

Allergy blood tests measure antibodies to a particular allergen in the blood, and ideal candidates for these tests are patients who fear multiple needle pricks, individuals with chronic skin disorders, and those patients who may have latex allergies.

The most common allergy blood test is the radioallergosorbent test (RAST). A person with an allergy produces specific antibodies called immunoglobulin E (IgE). The RAST test takes a measurement of IgE for different allergens and the results are normally available within 48 hours for the allergist to determine if the range is normal or abnormal. Treatment plans may include medications.

Patients seeking allergy relief should be honest with allergist about any medications to minimize false results and to obtain proper care.


The information in this article should not be considered medical advice. Always check with your physician before taking any products or following any advice you have read on Brighthub.com.