What is an allergy blood test?
Immunoglobulin E (IgE), a component found in your blood, is measured during an allergy blood test. Your body produces the antibody IgE. You could have higher levels of IgE in your blood than usual if you have allergies.
A frequent, chronic disorder involving your immune system is allergies. Your immune system produces antibodies to defend against bacteria, viruses, and other pathogens that might harm you. Your immune system misinterprets one or more innocuous items, such as pollen, as a threat leading to allergies. Your immune system produces IgE antibodies to combat the "threat." This is what causes your allergy symptoms.
Allergens are harmless substances that can trigger allergies. Typical allergens consist of:
- Animal dander
- Certain medicines, such as penicillin.
- Certain foods, including nuts and seafood.
The symptoms of an allergy vary and they may include sneezing,itching as well as asthma or the potentially fatal anaphylactic shock.
Other names: other names of this test are Quantitative IgE, IgE allergy test, Immunoglobulin E, Total IgE, Specific IgE, RAST, CAP, ELISA
What is the use of allergy tests?
Blood tests for allergies are performed to determine whether you have an allergy. The two main categories of allergy blood testing are:
- A total IgE test: To determine the overall concentration of IgE antibodies in your blood, a total IgE test is done.
- A specific IgE test: How much IgE your body produces in reaction to a particular allergen is determined by a specific IgE test. Each allergen that could be the source of your allergies is subjected to a separate test.
Why do I require a blood test for allergies?
If you experience allergy symptoms, your doctor may ask for allergy testing. These consist of the following:
If you are unable to have allergy skin testing, your doctor may decide to request an allergy blood test. A skin test includes injecting or applying allergens directly to your skin. Skin testing might not be an option for you if you:
- Have some skin conditions.
- Take certain medications that might affect the reports of the test.
- Are suspected to have a serious allergic reaction to the allergens used in skin testing.
Young children may require allergy blood tests in some circumstances since skin testing may be too unpleasant for them.
What happens during a blood test for allergies?
A tiny needle will be used by a medical practitioner to draw blood from a vein in your arm. A tiny amount of blood will be collected into a test tube or vial once the needle has been placed. The needle may hurt somewhat when it enters or exits your body. Usually, this only needs a few minutes.
How to prepare for the test?
An allergy blood test requires no extra preparation on your part.
Is there any risk associated with the test?
An allergy blood test carries relatively no risk or danger. One can have some little discomfort or bruising where the needle was inserted; but it vanishes soon.
What do the findings imply?
If your total IgE test result is high, you may have an allergy of some type. A total IgE test, however, does not reveal what you are allergic to or the potential severity of your allergy.
A high IgE test result for a particular allergen indicates that you could be allergic to that allergy. The severity of your allergy cannot be predicted by the quantity of IgE that was detected.
Your healthcare practitioner may suggest a course of therapy or send you to an allergy expert if the findings of either type of test indicate that you may have an allergy. Your allergy triggers and the severity of your symptoms will determine your treatment plan.
You must be very careful to avoid the substances you are allergic to if you are at risk for anaphylactic shock. An epinephrine auto-injector, which is an emergency treatment, may need to be carried by you at all times. The most frequent causes of anaphylactic shock include allergies to specific foods, medications, insect bites, and latex.
Ask your doctor if you have any concerns about your test findings or your allergy treatment Plan, as well as whether you are at danger for anaphylactic shock.
Important information to know about an allergy blood test?
Blood testing for allergies might not always be reliable. When you don't have an allergy, the findings can indicate that you do (also known as a false positive). This could occur if you ate particular meals before the test and your body has a mild reaction to certain ingredients. Rarely will a blood test reveal that you don't truly have an allergy when you do (also known as a false negative).
Your doctor may prescribe an allergy skin test along with an allergy blood test or only a skin test, depending on your medical history and symptoms.