The Allergy Scratch Test: Its Benefits and Drawbacks

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Millions suffer from allergies. For many people, the substance to which they are allergic is immediately apparent. (If you do not believe me, just ask anyone who learned the hard way that they are allergic to peanuts after munching a handful of them.) For others, however, their allergy-causing substance is not readily determinable. For these people, doctors commonly identify the culprit allergen by administering to the allergy suffer an allergy scratch test.

What Is An Allergy Scratch Test?

An allergy scratch test, or what is also known as an allergy skin test, is a very accurate diagnostic procedure in which an allergy sufferer’s skin is exposed to a variety of common allergens, with each allergen being administered to the skin at its own unique and identifiable spot. The allergic individual is then asked to return to the doctor’s office after a certain period of time, typically a few days or more later. At that time, the skin is observed for allergic reaction at each spot at which an allergen was added. A typical allergic reaction may be indicated by redness or the appearance of hives at a particular spot.

The test is referred to as a “scratch test” because the skin is scratched at each allergen spot to ensure that the allergen penetrates the surface of the skin such as to allow it to be exposed to the testee’s immune system, which is what causes the allergic reaction. If there is a reactive spot, the doctor likely will conclude that the allergen that was added at that spot, for example, pollen, is a substance to which the sufferer is allergic. The doctor could then advise the patient regarding which steps he/she can take to avoid, or at least minimize exposure to, the culprit allergen.

What Are The Benefits And Drawbacks Of An Allergy Scratch Test?

The most significant benefit to the allergy scratch test is obvious: the test helps identify a substance to which a person is allergic and such knowledge allows the person to best control his/her allergic outbreaks. Another benefit of the allergy scratch test is that it allows the doctor who administers it to determine to what degree someone is allergic to a certain allergen. For example, a mild response to dust mites would indicate that dust mites, while somewhat problematic to the person, are not something that the person need to be terribly concerned about. Conversely, a severe reaction to pet dander, for example, would mean that the person needs to take whatever steps necessary to avoid coming into contact with pets in order to avoid the miserable symptoms of a severe allergy outbreak.

One drawback to the allergy scratch test is that it can cause the person being tested to experience adverse symptoms, such as hives as mentioned above, for several days after the administration of the test. These symptoms sometimes are rather severe, especially when the person is significantly allergic to a particular substance that is included in the test. In extreme cases, tested people have become so ill that immediate and significant medical treatment is needed. This treatment may even include one or more night’s hospitalization. In very, very rare cases, the allergic reaction brought on by a scratch test can even be life-threatening. For these reasons, the decision to take an allergy scratch test should not be made lightly.

If you believe that you may be interested in taking an allergy scratch test, it is recommended that you contact your preferred allergy specialist. That individual can answer any questions that you may have regarding the safety and benefits of this test.


Mayo Clinic, Allergy Skin Tests:

Medline Plus, National Institutes of Health, Allergy Tests: