Health Encyclopedia  Diagnostic Procedures for Allergy     •
Nasal smears. Nasal smears are tests performed to check the
amount of eosinophils in the nose. Eosinophils are a type of
white blood cell that increases in number during an allergic
reaction.    • Blood tests. Blood tests for allergies measure
IgE (immunoglobulin E) antibodies to specific allergens in the
blood. The blood test most commonly used is called RAST
(radioallergosorbent test). Blood tests may be used when skin
tests cannot be performed. As with skin testing, it is important
to remember that a positive blood test does not always mean you
are allergic to that allergen.     • Skin tests. The skin test
is a very accurate test that measures your level of IgE
antibodies in response to certain allergens or triggers. Using
small amounts of solutions that contain different allergens,
the doctor will either inject under the skin or apply the
allergens with a small scratch. A reaction would appear as a
small red area. A reaction to the skin test doe