Radioallergosorbent test

A radioallergosorbent test (RAST) is a blood test used to determine the substances a subject is allergic to. This is different from a skin allergy test, which determines allergy by the reaction of a person's skin to different substances.

Because there are other tests that help with confirmation, results are best interpreted by a doctor. Since at least 2010, health organizations have recommended that the RAST be abandoned as a diagnostic test for allergy in favor of more sensitive fluorescence enzyme-labeled assays.