Food Allergies: Suspect, Test, Avoid
The Most Common Food Allergies continued...
The problem is that tests for food allergy are very sensitive. This means that if you do have a food allergy, the tests are very likely to catch it. But the tests aren't very specific. This means that the tests often are positive when there's no food allergy.
"People get 100 tests, and many are false positives and they end up chasing their tails," Oppenheimer says.
The new guidelines help doctors use food allergy tests in the best possible way. And when used properly, Portnoy says, testing works.
"Don't just assume you have a food allergy. If you suspect one, get it confirmed," Portnoy says. "You have to make sure you really are allergic. I have seen people with nutritional problems due to avoiding foods they're not really allergic to."
It's very rare for a person to be allergic to more than one or two foods, Oppenheimer and Portnoy say. So if testing is used to confirm or reject suspect foods, it is more likely to give meaningful results.
Once a food allergy is found, Muñoz-Furlong says, the real work begins.
"You have to learn how to manage the allergy on a day-to-day basis," she says.
FARE has a web site -- which both Oppenheimer and Portnoy recommend -- to help parents and adult patients manage their food allergies.
"Unfortunately, the only treatment we have is avoidance," Oppenheimer says. "But I have several suggestions that help. One is to wear a medical alert bracelet or necklace. And for restaurants, I am big fan of giving the server a card that shows what you are allergic to, and having the chef sign the card to make sure you aren't given anything you're allergic to."
Outgrowing Food Allergies
The new guidelines stress repeated testing to see whether a food allergy fades over time.
Many children with food allergies become tolerant to those foods over time. This is most likely to happen with allergies to cow's milk, hen's eggs, wheat, and soybeans. It's least likely to happen with peanut, tree-nut, and seafood allergies.
"So it's necessary to recheck patients to see if they are still allergic," Portnoy says.
When a person becomes less sensitive to a food to which they have been allergic, doctors call it "tolerance." It's hoped that scientists will one day learn how tolerance develops -- and how to induce tolerance.
"Why tolerance occurs is the million-dollar question in food allergy," Oppenheimer says. "We are working on it."