Tests used to identify and protect against food allergies may lead to misdiagnoses, according to a new study in the Journal of the American Medical Association.

A team of researchers examined medical articles that was published from 1988 to 2009, and found that not one publication had given a clear definition of what a food allergy was. Furthermore, they discovered that 82 percent of the papers printed their own definition and gave no clear direction of how doctors should make a diagnosis.

Typically, physicians have patients ingest the food in capsule form that is causing the reaction. Many allergists also use a skin-prick test to determine food allergies, which places extracts from the offending foods on the skin, and allows the physicians observed the reactions.

In the report, the authors stressed that these tests aren’t conclusive, stated that 50 percent of patients who experience reactions to skin-prick tests don’t have food allergies, which they found from the medical articles. They also felt that the definition of food allergies and guidelines for diagnosing patients needed to be more structured.

Marc Riedl, a section head of clinical immunology and allergy at the University of California in Los Angeles, said this article “validates the idea that there exists a great deal of complexity and confusion in the field of food allergy, even at the level of the medical literature.”

Approximately 4 percent, or one in 25 people in the U.S., have been diagnosed with food allergies, according to the Food Allergy & Anaphylaxis Network.