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Families coping with food allergies face a daunting task trying to avoid suspect foods. Now a new study suggests that many of these families are being burdened unnecessarily. Researchers meeting at a national allergy, asthma and immunology conference here in Washington this week, find that as many as half of childhood food allergies may be misdiagnosed.
NPR's Allison Aubrey has the details.
ALLISON AUBREY: There's no doubt that food allergies can be serious for many of the more than 12 million Americans who've got them. But increasingly, allergists are finding some people, particularly, young children, are avoiding foods they're not really allergic to. Take, for instance, Christy Littauer's three-year-old son Jack.
Ms. CHRISTY LITTAUER: When he was six-and-a-half months old, I gave him creamed spinach, and he basically stopped breathing. And we ended up going to the ER and then to an allergist. And he was diagnosed to have a strong allergy to dairy, eggs, wheat and peanuts.
AUBREY: Christy says she was convinced Jack was allergic to milk, given his reaction to the creamed spinach, but finding it hard to eliminate so many foods, she went for further testing at National Jewish Health in Denver. There, specialists performed a series of food challenges, basically under doctor's watch, Jack tried some of the foods that earlier blood tests suggested he was allergic to, including wheat.
Ms. LITTAUER: Now, he never had wheat in three years of life and that's a biggie. And lo and behold, he did not have a reaction, which was huge. It was like the sky has parted, and we said, we can give him wheat. This is amazing.
AUBREY: Now, Jack could eat a snack at a play date without his mom worrying. And the family could stop buying expensive wheat-free substitutes. Researcher David Fleischer, an allergist at National Jewish Health says stories like the Littauers show that relying just on blood tests is not enough.
In his most recent study presented today, Fleischer and his colleagues did food challenges with 125 kids, all of whom had allergies and eczema. They found that more than half the children were not allergic to all the foods they'd been told to avoid.
Dr. DAVID FLEISCHER (National Jewish Health): We did over 500 food challenges and 90 percent of our challenges were negative in these patients.
AUBREY: Fleischer explains they tested kids for the big five: soy, wheat, eggs, milk and peanuts, as well as a host of other foods, including fruits, fish, vegetables and meats, which are less common allergies.
Dr. FLEISCHER: So if you can imagine, between 4 and 20 foods in these children were being avoided unnecessarily in these children's diet.
AUBREY: Fleischer says as an allergist, the last thing he'd want to do is play down the seriousness of food allergies. But he says his findings point to the fact that many kids aren't getting proper diagnoses.
Dr. FLEISCHER: Blood tests can give you an idea that you may have a food allergy. It gives you a risk of sensitization to food. It doesn't necessarily mean that you're allergic to that food.
AUBREY: Allergist Richard Hendershot, who is in practice in Salt Lake City, says given that blood tests don't paint the full picture, he too recommends a combination of tests - talking to patients about the kinds of reactions they've had and food challenges.
Dr. RICHARD HENDERSHOT (Allergist, Salt Lake City): The food challenge is a very necessary part of the whole food allergy evaluation process because there are a lot of people who think they're allergic to something end up really not being allergic.
AUBREY: For kids who do have allergies, many ultimately outgrow common ones, such as to milk and eggs, but peanuts are tricky. Kids are less likely to outgrow peanut allergies. But there was news at the meeting this week that there may be a way to overcome peanut allergies. Duke University allergist Wesley Burks and his colleagues led the peanut study. After he gave children very small, but increasing daily doses of peanut protein over the course of several years, they were able to tolerate peanuts without reactions.
Dr. WESLEY BURKS (Allergist, Duke University): It really does give us hope that in the next few years, treatment will be available, but it's not ready now.
AUBREY: In other words, if you've got a kid with a peanut allergy, don't try this little bit of peanut approach at home. Experts say further studies are needed to prove whether this approach is safe.
Allison Aubrey, NPR News, Washington.