The "gold standard" of allergy testing is something called an oral food challenge, Riedl says, in which small amounts of the food in question are disguised and given to patient swhile they are under observation. This is best done if patients don't know if they are actually getting the food so they don't anticipate a reaction.
Unfortunately, this type of test is time-consuming, so many doctors are reluctant to do it, Riedl says.
Short of the food challenge, antibody levels and a past history of reactions, when interpreted by an experienced professional, are the best way to work through what is a food allergy and what is just a food aversion, or a bad case of indigestion.
With the help of the National Institute of Allergy and Infectious Diseases project, allergists hope that a clearer understanding of diagnosis and management of food allergies can be found.
"The amount of information we have now is very limited," Sampson says. "My hope for this article, and these guidelines, is that people who have control of funding will realize the need to put money into research on this. That would be a tremendous service."
In the meantime, according to ABC's senior health and medical editor, Dr. Richard Besser, if you are concerned you might have a food allergy, you should see a doctor.
"The most important thing your doctor will do is to ask you what happened when you ate the food, and whether you might have symptoms such as runny nose, itchy skin, rash," he says.
For adults who have been told in the past that they have a food allergy, but have not had a reaction in four or five years should be retested, Besser says.
"It is important to reintroduce foods under the supervision of a doctor, because there is a small chance that a person could have a severe reaction," says Besser.