Allergy testing is done to find out if you are allergic to a specific substance (allergen) and to determine proper prevention and treatment. Some common allergens include insect bites, mold, pollen, latex or animal dander. The testing can also be done to find the possible cause of certain conditions (asthma, hay fever and skin irritation). Two methods of allergy testing are skin tests and blood tests.

• Skin tests involve placing a small amount of a certain substance into the skin to see if redness and/or swelling develop. This can be done by putting the substance on the skin and making a very small scratch (prick test). It can also be done by injecting the substance under the skin with a small needle (intradermal test). Reactions are usually seen within 15 to 20 minutes. Skin testing is the most common form of allergy testing.
• Sometimes skin testing cannot be done. This can happen if you are taking a medication that interferes with the results or you have certain skin conditions, such as eczema. In those cases, blood tests can help determine the cause of some allergy symptoms. For example, your blood can be combined with particles of a potential allergen to see if there is a response. This is called a RAST test. RAST tests are not routinely done because they are more costly and may not be as accurate.

Most people with allergies do not need allergy tests. In most cases, your healthcare provider can determine the cause of your symptoms by taking a careful history and performing a physical examination. If your symptoms cannot be controlled with the medications or avoidance, you may be referred to a trained specialist (such as an allergist-immunologist) for allergy testing. He or she will review your medical history and do a physical examination. Keeping a daily diary of your symptoms may also be recommended.

Prior to having allergy testing, tell your healthcare provider about any medications you are taking (including over-the-counter medications and supplements). Also ask about medications you should not take before skin testing.

• Antihistamines can prevent your body from reacting to the substances. This can result in a false negative result.
• Some antidepressants, heartburn medications and asthma medications can also interfere with allergy testing.

Skin testing can't be done under some circumstances, such as when you're taking a medication that may interfere with the results or if you have certain skin conditions, such as eczema. In those cases, blood tests may be done instead.

This care path includes the costs of an office visit, fifty scratch tests and fourteen intradermal tests. The number of units billed by your healthcare provider may deviate from this. In order to accurately determine your costs, ask your healthcare provider how many of each allergy tests he or she is going to perform.

When you are seeing a healthcare provider about allergy testing, be prepared to discuss your symptoms, how long you have had them and what makes them worse or better.

• Bring a copy of your medical history (past illnesses, surgeries, and hospitalizations).
• Make a list of your medications (including over-the-counter).
• If your healthcare provider wants you to take a medication, ask if an over-the-counter product is right for you.
• If your healthcare provider prescribes a medication for you, ask for a generic version. If your doctor thinks that a generic version is not right for you, ask for a medication on the lowest available tier of your Prescription Drug List (PDL).

Here are some questions to ask your healthcare provider.

• How many allergy tests will you be doing? How many are scratch tests? How many are intradermal tests?
• What is my follow-up plan and what symptoms should I report before my next appointment?

Source UHC.com

Also known as:

Skin Test

Scratch Test

RAST test

Intradermal Test

Allergy Testing

Allergy Symptoms

Allergies

Allergic