Pricks aren't to be trusted

Doubt Is Cast on Many Reports of Food Allergies - NYTimes.com

“Everyone has a different definition” of a food allergy, said Dr. Jennifer J. Schneider Chafen of the Department of Veterans Affairs’ Palo Alto Health Care System in California and Stanford’s Center for Center for Primary Care and Outcomes Research, who was the lead author of the new report. People who receive a diagnosis after one of the two tests most often used — pricking the skin and injecting a tiny amount of the suspect food and looking in blood for IgE antibodies, the type associated with allergies — have less than a 50 percent chance of actually having a food allergy, the investigators found. ...

But for now, Dr. Fenton said, doctors should not use either the skin-prick test or the antibody test as the sole reason for thinking their patients have a food allergy.

“By themselves they are not sufficient,” Dr. Fenton said.