IgE Serum Testing for Allergies vs Skin Prick

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As quoted from Medscape:

“Specific IgE testing can be done through skin testing or blood testing. Testing should be based on the clinical scenario.”

In vitro tests assess antigen-specific IgE by testing the patient’s serum. Advantages to this method include the use of a single venipuncture that is not affected by medications. In vitro testing can be performed on patients with affected skin, such as dermatographism or atopic dermatitis. It is also a safer option if the patient is at risk for anaphylaxis. However, these tests are expensive compared with skin testing.

In this method, immunoassays measure interactions between antigens and antigen-specific antibodies. Immunoassays are often referred to as radioallergosorbent (RAST) testing, but that term is outdated because radiation is rarely used today. Current methods include enzyme-linked immunosorbent assay (ELISA), which uses antibodies linked to enzymes, as well as fluorescent enzyme immunoassays (FEIA) and chemiluminescent immunoassays, which use fluorescent generation with an enzyme.”

This method described on Medscape, the enzyme-linked immunosorbent assay or ELISA is the exact methodology performed by Infinite Labs. This is well established and routine. 

As stated by Dr. Portnoy, MD in the publication Appropriate Allergy Testing and Interpretation:

“For the primary care provider, in vitro tests have the advantage that they are readily available, they require a single venipuncture, the office staff do not need to be trained to perform them, there is no risk to the patient since directed exposure to the allergen is avoided, and the tests are not affected if the patient has taken an antihistamine.”