Q:

6/20/2013
The role of component testing in food allergies: With recent publications supporting the clinical validity of component testing, do you have any advice on utilizing this in clinical practice in those with food allergies? Could you please provide scenarios where it can offer additional information that can be applied clinically (especially considering the high cost) in relationship to the skin prick test and IgE testing?

A:

Thank you for your inquiry.

The role of component testing in the diagnosis and management of patients with food allergy is constantly evolving. To discuss this in detail, citing various clinical examples, would be beyond the scope of our website, but I will mention its major role, and below you will see articles discussing this issue in more detail. You might find the video presentation by Dr. Hugh Sampson, which was given at the American Academy of Allergy, Asthma, and Immunology meeting in February, quite helpful. The link will take you directly to his lecture which can be seen in its entirety.

Put simply, at present, the main role of component testing is to enhance the predictability of a positive allergy test (either serum specific IgE or a skin test) to the "whole food allergen". That is component testing is designed to sharpen our ability to define whether or not a patient with a positive test will react to the ingestion of the food in question. Foods contain many allergens. Some of these, even though the patient has specific IgE antibody against that allergen, would not produce a reaction when the patient ingests the food in question.

Component tests allow us to sharpen our diagnostic accuracy by testing to several allergens, simultaneously, within that food. Based upon previous oral food challenges and experience, we have learned that some of these allergens will more frequently be associated with a reaction when ingested than others. Some will mainly produce oral allergy (oral allergy syndrome/fruit-pollen syndrome). By testing for specific components, one would be able to better predict whether or not a test to that whole food would be associated with a reaction on ingestion. Such component testing, however, still lacks 100% efficacy, and an oral challenge would be the only way to be sure that the food was safe to ingest. Nonetheless, component testing can be done to better help assess whether or not an oral challenge would be safe.

Thank you again for your inquiry and we hope this response is helpful to you.

Diagnosing food allergy: NIAID Guidelines and the emerging role of component testing.
Hugh Sampson, MD of the Mt. Sinai School of Medicine and The Jaffe Food Allergy Institute presents on the NIAID Food Allergy Guidelines and allergen component diagnostics a YouTube video.

The diagnosis of food allergy: Lieberman, Jay A.; Sicherer, Scott H. American Journal of Rhinology & Allergy, Volume 24, Number 6, November/December 2010, pp. 439-443(5).

Diagnosis of food allergy: epicutaneous skin tests, in vitro tests, and oral food challenge.
Lieberman JA, Sicherer SH. Curr Allergy Asthma Rep. 2011 Feb;11(1):58-64. doi: 10.1007/s11882-010-0149-4.

Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology