Everything You Should know about Allergy Blood Test
The allergy blood test calculates a substance known as immunoglobulin E (IgE) in the blood. This antibody is made by the body and when you have allergies, there may be more IgE in the blood.
Allergies are a common condition which involves the immune system for a long term. The immune system makes antibodies to fight against bacteria, viruses and other things that may make you feel sick. Due to allergies, the immune system treats one or more risk-free substances like peanuts or pollen in the form of threat. In order to fight the “threat,” your immune system prepares IgE antibodies and this causes allergy symptoms.
Harmless substances that can lead to allergies are known as allergens. Common allergens are the following:
- Dust
- Pollen
- Mold
- Some foods such as shellfish and nuts
- Animal dander
- Certain medicines like penicillin
The symptoms depend on the kind of allergy you have. This may range from sneezing and itching to asthma or life-threatening condition known as anaphylactic shock.
What it is used for
Allergy blood tests can be used to detect whether you are having any allergy. There are two kinds of allergy blood tests:
- A total IgE test – This can be used to detect the entire amount of IgE antibodies in the blood.
- A specific IgE test – This denotes the amount of IgE your body prepares for a single allergen. You need to conduct a separate test for each allergen that may cause the allergies.
Why you require an allergy blood test
The health care provider may order private allergy tests when you have possible symptoms of an allergy. Some of these are the following:
- Sneezing
- Vomiting
- Runny or stuffy or runny nose
- Wheezing
- Coughing
- Watery or itchy eyes
- Diarrhea
- Hives
- Shortness of breath
The provider may select allergy blood test when you cannot perform allergy skin test. Your skin test includes putting the allergens directly on or in your skin. You might not be able to conduct skin tests if you:
- Suffer from certain skin problems
- Have the probability of getting serious allergic reaction to allergens used in skin tests
- Take some medications that can affect the test results
There are some cases when the providers ask children to conduct allergy blood tests as skin testing might be very uncomfortable for them.
What happens for conducting an allergy blood test?
The health care provider collects blood sample from the vein in your arm with a small needle. Once the needle gets inserted, a small amount of blood will be collected into the test tube or vial. You will feel slight sting when the needle goes in or out. This generally requires less than five minutes.
Should you do anything to prepare for the test?
You do not require special preparations for performing an allergy test.
Are there any risks with the test?
There is little risk involved with conducting an allergy blood test. You might get slight bruising or pain at the spot where the needle was put in, but most symptoms will go away quickly.
What will the test results mean?
A total IgE test result which is high means you are suffering from some kind of allergy. But the results of a total IgE test do not reveal what you have been allergic to or how serious the allergy can be.
A specific IgE test result which is high means you might feel allergic to certain allergens that were tested. But the amount of IgE calculated do not denote how serious your allergy might be.
If the results from either of these tests denote you have an allergy, the provider may refer you to an allergy specialist or suggest for a suitable treatment plan. The treatment plan depends on what you can be allergic to and how serious the symptoms might be.
When you are at risk for getting anaphylactic shock, you should be extremely careful to prevent the things you are allergic to. Anaphylactic shock is very common with allergies to certain foods, medications, stings, latex and insect.
Ask the provider whether you are at greater risk for getting anaphylactic shock and discuss necessary questions you might have about the test results or your allergy treatment plan.
Is there anything you should know about an allergy blood test?
Allergy blood tests might not be accurate all the time. Sometimes, the results denote you are having an allergy even when you do not. This might occur is your body has some reaction to substances in certain foods before conducting the test. It is quite uncommon for private blood tests to show you do not have allergy when you actually have it.
Depending on the medical record and present symptoms, the health care provider may order an allergy skin test along with an allergy blood test, or you may need to perform a skin test alone.
