Allergy Blood Test
Allergy Blood Test
Allergy blood tests help diagnose allergies by measuring the amount of allergen-specific antibodies present in the blood. The test is conducted by drawing a small amount of blood from the upper arm and checking it for immunoglobulin levels, in particular IgE antibodies. These IgE antibodies are produced when the body is exposed to a certain allergen.
Preparation
The preparation for an allergy blood test is very simple. You do not need to fast for the test, and you do not need to stop taking any medications or stop eating any foods. You should advise your healthcare provider if you are taking any medications that might affect the results, such as antibiotics, birth control pills, antacids, or steroids.
Procedure
The procedure for an allergy blood test is quite simple. First, your doctor will draw a small amount of blood from your arm using a needle. The blood will be sent to a lab for analysis. The analysis will determine the levels of specific immunoglobulins, or IgE, in the blood, which are specific to the allergens being tested.
Types
There are two types of allergy blood tests currently available: the RAST test (which stands for radioallergosorbent test) and the ELISA (which stands for enzyme-linked immunosorbent assay) test. The ELISA test is more sensitive than the RAST test and can detect more allergens with greater accuracy.
Risks
The risks associated with an allergy blood test are very low. Since only a small amount of blood is drawn, the risk of infection is minimal. There may be some bruising or minimal bleeding at the area from which the blood is drawn.
Why
Allergy blood tests are used to accurately diagnose allergies in a person that is suspected to have one. The test allows the doctor to detect the presence of IgE antibodies, which are specific to certain allergens, in the blood. By identifying the triggers of an allergic reaction, the doctor can determine the appropriate treatment for the allergy.
When
An allergy blood test is recommended when other types of allergy testing, such as skin prick tests and elimination diets, are not useful or have a high chance of producing false results. An allergy blood test can also be used to identify and monitor allergies in patients with suppressed immune systems, such as those taking steroids or undergoing chemotherapy.