Allergy Blood Tests

Allergy blood tests

There are lots of tell-tale signs to look for if you think you might be experiencing allergy symptoms. Signs such as frequent sneezing, itchy or watery eyes and a congested nose. You may experience problems when you eat certain foods. All of these symptoms could be related to allergies. But how do you know for sure?

One way a health care provider may start the process of diagnosing allergy is referring you for an allergy blood test. In this article, we’re going to look at when an allergy blood test could be done and how the test is performed. We’ll talk about how accurate allergy blood testing is, and we’ll also explain what the test results can show.

What is an allergy blood test?

An allergy blood test is the same as any other blood test: a small amount of your blood is sent to a lab for analysis.

Allergy blood tests can detect Immunoglobulin E (IgE) in your blood. IgE is an antibody produced by the immune system in connection with a reaction to protect us from outside intruders such as parasites.

Allergy blood tests identify and measure IgE antibodies in your blood. This can help to pinpoint what triggers your allergies.

When you’re allergic to for example pollen, certain foods or insect stings your immune system overreacts to the otherwise harmless substance and triggers the same defense mechanisms as against parasitic infections. The body produces IgE antibodies specific to the allergen it’s trying to fight. These antibodies tell cells in your body to release certain chemicals. And it’s those chemicals that cause allergy symptoms.

Allergy blood tests identify and measure specific IgE antibodies in your blood. Since IgE antibodies are different depending on what they are reacting to, allergy blood testing can point to what allergens your body is reacting to.

Allergy blood tests show if you're sensitized

An allergy blood test can be the first step to finding out if you have an allergy.

Think of the results of an allergy blood test as a sign of a suspected allergy rather than stand-alone proof. You basically get a risk profile of which allergen you might be allergic to.

When it comes to understanding how allergy blood testing works and how results are interpreted, it’s important to note that the presence of IgE antibodies in your blood does not necessarily mean you are allergic. It means that you are sensitized.

Sensitization or allergy

Sensitized or allergic
What's the difference?

Sensitization vs allergy

Sensitization is the first step in developing an allergy. Allergic reactions do not happen the first time you encounter an allergen. First, your immune system has to register the allergen and build the specific IgE antibody against it. This process is called sensitization.

If you’re allergic, the next encounter with the allergen might then trigger an allergic reaction. However, some people are sensitized and have specific IgE antibodies, but don’t experience any allergic reaction no matter how often they are in contact with the allergen.

That means an allergy blood test shows if you’re sensitized to a specific trigger. Not that you are necessarily allergic to it. Only in connection with your symptoms and medical history a health care provider will be able to interpret the results in order to give a diagnosis of allergy.

When should allergy blood tests be done?

If your allergy symptoms are mild and the cause is obvious, your health care provider will be able to offer advice and discuss treatment options with you. But you may be referred for an allergy blood test of a specific range of triggers if your allergy is more severe or it’s not clear what’s causing your symptoms.

Skin prick tests

Skin prick tests

Skin prick tests are one of the most common methods to test for allergy, but there are times when a blood test for allergy may be done along with skin prick tests or even instead of skin prick tests.

Allergy blood tests are especially useful if you have a skin condition. Or if you are taking certain medications that could interfere with the skin prick test results. They may also be used if the results from skin prick tests did not give clear results.

How are allergy blood tests performed?

Many of us will have had a blood test at some point in our lives. A small amount of your blood is taken from a vein in your arm or a finger and sent to a lab for analysis. Collecting a blood sample is usually only temporarily uncomfortable.

Your blood sample will be sent to a laboratory and tested against the allergens your doctor has chosen for the test. When your allergy blood test results are ready you will need to go back to your health care provider to discuss them.

How accurate are allergy blood test results?

Overall, the accuracy of blood tests for allergy is high. Blood tests are evolving all the time and getting more precise. Some blood tests are now able to give results for individual proteins in a single allergen.

What to do after allergy blood testing

Knowing exactly what you are allergic to means you’re better equipped to manage your allergy symptoms. You’ll be able to discuss your treatment options with your health care provider and make decisions that are right for you.

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If you’ve read all the way to the end of this article, thank you. And we’d love to know what you think. Are you considering being tested for allergy? Have you already had an allergy test done? Has knowing what you’re allergic to made a difference for you? Head over to our Facebook page or email us and share your story.


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