Allergy Testing: Types of Allergy Test
Taking an allergy test helps in verifying if an allergy is the cause of the reactions and what substances you are allergic to. Even if one is not chronically allergic, certain plants and pollen can cause seasonal allergies, and a person may find themselves developing allergic symptoms such as hay fever and allergic rhinitis.
In this article, you will learn how to prepare for an allergy test, what to expect, and the different tests done for allergies.
Types of Allergy Tests
There are two major types of allergy tests:
Skin allergy tests
Skin allergy tests are a popular method to test patients for allergic reactions. There are three types of skin allergy tests.
1. Skin prick test
This is also known as the scratch test, where the suspected allergen is placed on your back or forearm, and the site is pricked so that the allergen enters the body system.
The doctor then observes the skin area closely for any reactions. The test is done for multiple suspected allergens at once. In such cases, the procedure is carried out on multiple skin points using the different suspected allergens.
It is important to note that this test isn’t solely for testing skin allergies. If one suspects a food allergy, a skin prick test can also be used for food allergy testing. The doctor introduces a liquid that contains protein from the suspected food into your body through a prick. If one is allergic to food, there will be reactions at the test site.
2. Intradermal test
In the intradermal test, doctors inject a small amount of the suspected allergen just under the skin, and the skin surface is observed for a few minutes for reactions.
Intradermal injections are mainly administered on the forearm, upper arm, or back. A positive test will result in swelling, redness, or an itch. This test is mainly used for testing penicillin and insect bite allergies.
3. Patch test
A patch test is another method of allergy testing involving the skin that is effective in identifying the causes of the allergy.
It does not involve needles. Instead, a patch embedded with several suspected allergens is attached to your skin. You are required to wear the patch for up to 48 hours, and during this time, you avoid bathing or activities that will make you sweat.
At the end of the 48 hours, the person should visit the doctor; the doctor then removes it and checks the results.
With a patch test, you can determine which skin allergy types you have. If you react to any of the tested substances, that is the allergen, and you must avoid it.
Blood Allergy Tests
When you have an allergy, your body produces a high level of immunoglobulin E (IgE), an antibody. Blood allergy tests look for these antibodies in your blood to identify allergies.
Blood allergy tests are of two types:
- Total IgE test: In the total IgE test, the total amount of IgE in your blood is examined. It does not show you the type of IgE present or the type of allergy you have.
- Specific IgE test: This test measures the amount of IgE created in response to a particular allergen. There is a specific IgE test for each allergen.
Skin test vs blood Test: Which one should you go for?
Skin tests are the most common as the results are given immediately, especially with the skin prick and intradermal tests. On the other hand, blood tests take much longer for the results to be out.
However, if a person has skin conditions such as hives on the skin or rashes or is taking antihistamines, the blood allergy test is a better choice for them.
Can a Person Take Allergic Tests If You Suffer Anaphylaxis?
Anaphylaxis is a severe health condition that can result from exposure to an allergen but can be effectively treated with epinephrine injection.
When a person goes for an allergy test, necessary precautions are put in place, and a person is placed under close observation for any sign of anaphylaxis.
Depending on the results of the tests and the severity of the condition, the allergist may prescribe medicines in case any emergency happens in day-to-day activities.
Allergy tests are the surest way to confirm if a person has an allergy and to determine its type and cause. When a person goes for an allergy test, the doctor prescribes the necessary medications. If a person is having allergy symptoms, do not delay getting tested to avoid allergens in the future and get the necessary treatments.
