Radioallergosorbent testing, or RAST testing, used to be the go-to blood test for helping to diagnose an allergy. However, newer allergy blood tests are now available. ImmunoCAP testing is a more common allergy blood test. Your doctor could also order an enzyme-linked immunosorbent assay, or ELISA test.

What is the difference between RAST and ImmunoCAP?

Radioallergosorbent testing, or RAST testing, used to be the go-to blood test for helping to diagnose an allergy. However, newer allergy blood tests are now available. ImmunoCAP testing is a more common allergy blood test. Your doctor could also order an enzyme-linked immunosorbent assay, or ELISA test.

What does a RAST test show?

A RAST test or radioallergosorbent test is a way of testing a person’s blood to see if they have any allergies. This test checks their blood for specific lgE antibodies to find out what substances they may be allergic to. Allergies can be a mild annoyance or a life-threatening condition.