No reaction in 86 percent of those tested; 98 percent with no anaphylaxis.

The best way to find out if someone has a food allergy is through an oral food challenge (OFC) where the person is given a very small dose of the food by mouth under the supervision of a board-certified allergist to test for a severe reaction. A new study shows that OFCs are extremely safe, with very few people having a reaction of any kind.

The study in the journal Annals of Allergy, Asthma and Immunology examined the results of 6,327 OFCs. The majority of those tested were under the age of 18. Researchers found about 2 percent of those being tested had a severe allergic reaction, also known as anaphylaxis, and only about 14 percent had any reaction at all.

“Oral food challenges are a very important tool for anyone who wants to know if they have a food allergy,” said allergist Kwei Akuete, MD, MPH, ACAAI member and lead author of the study. “As OFCs are the ‘gold standard’ for determining if someone is allergic to a food, it is important they are both effective and safe. Our study showed OFCs are safer than prior studies estimated, and that OFCs should be routinely used to help determine if a food allergy exists.”

Reactions to OFCs that weren’t classified as anaphylaxis involved only one part of the body – such as hives on the skin. They were considered mild to moderate – not severe – and were mostly treated with antihistamines. The OFCs were performed at five food allergy centers throughout the US.

“Food challenges improve the quality of life for people with food allergies, even if they are positive,” said allergist Carla Davis, MD, ACAAI member and study senior author. “When an OFC is delayed, sometimes people unnecessarily cut certain foods out of their diet, and this has been shown to lead to increases in health costs to the patient. A delay risks problems with nutrition, especially for children. It’s important to have an accurate diagnosis of food allergy so an allergist can make a clear recommendation as to what foods you need to keep out of your diet. And if no allergy exists, that clears the way to reintroduce foods you may have thought were off-limits.”