When Food Is A Danger

"I can't rely on a lot of processed foods, because soy and dairy are in almost everything," says Perkins, who has been diagnosed herself with an allergy to fresh apples -- although cooked are okay -- and to cantaloupe.

Doctors diagnose food allergies through blood and skin tests coupled with a physical exam and a history of food-related problems. Studies suggest that about 30 percent of people who think they are allergic, prove not to be.

Any food can produce an allergic attack, notes allergist Paul J. Hannaway, author of "On the Nature of Food Allergy."

But Robert A. Wood, a doctor at Johns Hopkins University, wrote in a report in the journal Pediatrics in 2003 that just eight foods -- milk, eggs, peanuts, tree nuts, fish, shellfish, soy and wheat -- account for about 90 percent of the food allergy reactions in the United States. Allergy to milk proteins is the most common in the United States. (This allergy is different from lactose intolerance, a condition that causes intestinal distress and other problems and afflicts 30 million to 50 million Americans who don't have an enzyme needed to digest the sugar, lactose, found in dairy products.)

The only sure way to manage food allergies is to avoid foods that cause the reactions and to be prepared for the problems that can be caused by accidental exposure.

Sometimes even the experts can be fooled.

Wood, who has a peanut allergy, was once given homemade cookies by a grateful patient's parent. He was assured that the cookies did not contain peanuts. But they had been baked on a cookie sheet that had previously baked cookies with peanuts. The residue was enough to send Wood into an anaphylactic attack that required three shots of epinephrine to reverse.

Since January 2006, the Food and Drug Administration has required food manufacturers not only to list leading food ingredients that could cause allergies, but also to indicate if products had been produced on equipment that could contain residues of allergy-causing foods such as peanuts or soy.

But a study published last week suggests that the warnings are now given so frequently that "consumers assume they are not serious," notes the study's co-author, Scott Sicherer of the Jaffe Food Allergy Institute at Mount Sinai School of Medicine in New York.

The study also found that the warnings "do not reflect the degree of danger" for those with food allergies.

That's why longtime food allergy sufferers often yearn for something that will eliminate their condition. "I wish there was something new for treatment," Paganelli says.

There may be. Burks and his colleagues at Duke are one of several groups exploring ways to help tame overreactive immune systems. Results have been promising enough that Burks predicts some treatment could be available in the next five years.