Allergy Tests

When you need them and when you don’t

Allergy tests may help find allergies to things you eat, touch, or breathe in. They are usually skin or blood tests.

However, allergy tests alone are generally not enough. It is important to have a doctor’s exam and medical history first to help diagnose allergies. If the exam and medical history point to allergies, allergy tests may help find what you are allergic to. But if you don’t have symptoms and you haven’t had a medical exam that points to an allergy, you should think twice about allergy testing. Here’s why:

Allergy tests, without a doctor’s exam, usually are not reliable.
Many drugstores and supermarkets offer free screenings. And you can even buy kits to test for allergies yourself at home. But the results of these tests may be misleading.

  • The tests may say you have an allergy when you do not. This is called a “false positive.”
  • These free tests and home tests for food allergies are not always reliable.

Unreliable test results can lead to unnecessary changes in your lifestyle.
If the test says you are allergic to some foods, such as wheat, soy, eggs, or milk, you may stop eating those foods. You may end up with a poor diet, unnecessary worries and frustration, or extra food costs. If the test says you are allergic to cats or dogs, you may give up a loved pet.

And tests for chronic hives—red, itchy, raised areas of the skin that last for more than six weeks—can show something that may not look normal but is not a problem. However, this can lead to anxiety, more tests, and referrals to specialists.

The wrong test can be a waste of money.
Allergy tests can cost a lot. A skin allergy test can cost $60 to $300. A blood test can cost $200 to $1,000. A blood test for food allergies can cost hundreds of dollars, and testing for chronic hives can cost thousands of dollars. Your health insurance may not cover the costs of these tests. And without a doctor’s exam, the test may not even tell you what is causing your symptoms or how to treat them.

So, when should you have allergy tests?
If you have allergy symptoms, you may get relief from self-help steps and over-the-counter drugs. We talk about these in the blue section at right. If these steps do not help your symptoms, then it is time to see your doctor.

The doctor should ask you about your medical history and make sure you get the right tests. If your medical history suggests that you have an allergy, your doctor might refer you to an allergist or immunologist (doctors who specialize in allergies) for testing.

  • A skin test is the most common kind of allergy test. Your skin is pricked with a needle that has a tiny amount of something you might be allergic to.
  • If you have a rash or take a medicine that could affect the results of a skin test, you may need a
    blood test.
  • For chronic hives, you usually do not need an allergy test. However, your doctor might order
    tests to make sure that the hives are not caused by other conditions, such as thyroid disease,
    lymphoma, or lupus.

This report is for you to use when talking with your health-care provider. It is not a substitute for medical advice and treatment. Use of this report is at your own risk.

© 2012 Consumer Reports. Developed in cooperation with the American Academy of Allergy, Asthma & Immunology. To learn more about the sources used in this report and terms and conditions of use, visit