What are they?
Allergy blood tests look for substances in the blood (antibodies)
that the body makes in response to allergens. Allergens are things that the
body is allergic to.
There are several types of allergy blood tests
including:
- Enzyme-linked immunosorbent assay (ELISA,
EIA).
- Radioallergosorbent testing (RAST).
- Immunoassay
capture test (ImmunoCAP, UniCAP, or Pharmacia
CAP).
- Fluoro-allergosorbent testing (FAST).
- Multiple
antigen simultaneous testing (MAST).
Why are these tests done?
Allergy blood tests are
done to find out what things you are allergic to.
What happens during these tests?
The health
professional taking a sample of your blood will:
- Wrap an elastic band around your upper arm. This makes the
veins below the band larger so it is easier to put a needle into the vein.
- Clean the needle site with alcohol.
- Put the needle
into the vein.
- Attach a tube to the needle to fill it with
blood.
- Remove the band from your arm when enough blood is
collected.
- Put a gauze pad or cotton ball over the needle site as
the needle is removed.
- Put pressure on the site and then put on a
bandage.
What else should you know about these tests?
The
results of allergy blood tests are usually available in about 7 days.
