Enzyme-linked immunosorbent assay (ELISA) In vitro basophil histamine release assay Radioallergosorbent test (RAST) Allergy blood tests, which are less sensitive and more expensive than skin tests, are usually reserved for rare cases when allergy skin tests may not be accurate (e.g., when the patient has sensitive skin that reacts to a saline prick test or has a skin condition, such as hives or ec