Lab tests an allergist may order during diagnosis may include:

• Allergen skin test: In this test, the allergist introduces tiny amounts of an allergen under the patient's skin with a pin-prick. In an allergic patient, the allergen will produce a swollen itchy patch surrounded by an area of redness. Usually, this office procedure can test for several allergens at the same time.
• Radioallergosorbent blood test (RAST): This blood test determines the presence of IgE antibodies in the blood. High levels of these antibodies point to particular allergies. The RAST blood test is not considered as accurate as the allergen skin test.