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May 11, 2022 | Allergies

How Does Allergy Testing Work?

Woman sneezing next to a cat and flowers

Peanuts. Pollen. Pet dander.

These are just some of the allergies that more than 50 million people in the U.S. suffer from each year1. Because allergies are so common, they are considered the sixth leading cause of chronic illness1. With many allergy triggers at play, ranging from food to the environment, it may be hard to know which allergens are affecting you. Thankfully, there are two types of allergy testing methods to help you out.

What are the types of allergy tests?

Think you might have an allergy but not entirely sure what you might be allergic to? Talking to your primary healthcare provider or an allergist about allergy tests can be a good place to start. There are two methods for allergy testing:

  • Skin allergy tests. This is the most common type of allergy testing and is often considered the gold standard2. There are two skin allergy testing methods:
    • Pick or scratch test. Out of the two methods, the prick or scratch test is the most common. A tiny drop of an allergen is pricked or scratched into the skin. The skin is then closely observed for a reaction to determine if there is an allergic reaction. Multiple allergens can be tested at once and results are typically produced within twenty minutes3.
    • Intradermal test. An intradermal test involves injecting a tiny amount of an allergy under the skin with a small needle. Similar to the pick or scratch test, the injection site will be observed for a reaction. Additionally, intradermal tests typically focus on finding out if you’re allergic to insect stings or penicillin3.
  • Blood allergy tests. When your body senses a perceived threat to the immune system (in this case an allergen), antibodies called immunoglobulin E (IgE) are made. A blood allergy test is used to see the levels of IgE antibodies in your blood. A small amount of IgE is normal, while larger amounts can signal an allergy. There are two types of IgE blood tests4:
    • A total IgE test measures the overall amount of antibodies in your blood
    • A specific IgE test measures the level of IgE antibodies in response to individual allergens

Does allergy testing need to be repeated?

Depending on your allergies and treatment plan, your healthcare provider may want you to be retested. Allergy retests may be ordered based on symptom or therapeutic changes5.

  • Symptomatic reasons for allergy retesting. If you’re already on allergy medication and feel like it’s not working, or noticed that you may be allergic to something new, your allergist may want to complete more testing. Allergies aren’t static, meaning they can change through the course of your life. What you may once have been allergic to may stop being a trigger, or you may pick up an allergy to something else, say pollen instead of grass.
  • Therapeutic reasons for allergy retesting. Depending on the severity of your allergies, your allergist may order that you participate in immunotherapy, which would take place in the form of an allergy shot. Immunotherapy is meant to increase your body’s ability to fight off allergens. When doing immunotherapy, you are getting injections with a small amount of the allergen. Over time these doses are increased which makes your immune system stronger and better prepared to handle these allergens. Allergy retesting can help your healthcare provider understand if the treatments are working6.

Can you test for allergies at home?

Since allergies can be uncomfortable with itching and sneezing, and the same can happen during skin allergy testing, it may sound ideal to complete allergy testing in the comfort of your home. However, this sadly isn’t the case yet and skin allergy tests need to be completed in a healthcare provider’s office. The good news is that for blood testing, Scarlet® can meet you where you are to collect a sample for your blood allergy test. While the allergy testing itself isn’t performed in your home, one part of the allergy test process can be easier by getting your blood draw completed at home. From there, your blood sample is delivered to a BioReference laboratory for testing and hopefully know the source of your allergy discomfort. Additionally, Scarlet collaborates with Curex, an online allergy clinic, to make at-home allergy test collection possible.




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