New Thinking About Diagnosis and Prevention of Food Allergies in Kids

By Christina Elston

PB & J SandwichIf your child has a food allergy – or attends a peanut-free classroom – then you know how serious this diagnosis in kids can be.

In December, a seventh-grader in Chicago died after reportedly suffering an allergic reaction to food served at a classroom party, prompting renewed debate over Illinois policies for handling food allergies in the schools.

Schools nationwide have confronted an increase in food allergies over the last two decades with policies that ban certain foods from the classroom, school parties and designated tables in the cafeteria. Restaurants and food vendors now post signs urging customers to let servers know whether they have a food allergy before ordering.

Food allergies – particularly those serious enough to cause death if not treated immediately – are frightening, especially for parents who must ensure that their kids are protected from accidental exposure to allergens outside the home. And millions of kids in the United States (about 3 million in 2008, according to the national Centers for Disease Control) are currently diagnosed with them.

But the upsurge in food allergy cases – tripling between 1997 and 2006, government research shows – has prompted concern, some skepticism and new thinking. Now, new federal guidelines suggest that parents and health providers pay more attention to how a food allergy diagnosis is made.

Among other things, the guidelines, released in December 2010 by the National Institute of Allergy and Infectious Diseases (NIAID) and a panel of experts, stress that doctors should not rely on any single test to determine whether or not someone is allergic to a particular food.

Tools for a Proper Diagnosis

That recommendation suggests that the increase in food allergy cases over the years has been accompanied by at least some misdiagnosis – probably because doctors rely too much on blood tests or skin-prick tests alone.

Stanley Fineman, M.D., president-elect of the American College of Allergy, Asthma and Immunology, was not involved in writing the new guidelines, but says that only an allergist is likely to test thoroughly enough for a good diagnosis of food allergies. Anyone identified as having food allergies based on “one blood test in one office one time” might benefit from letting an allergist take a closer look, he says.

Tools an allergist might employ include taking a health history, performing a full medical evaluation, a blood test, and a skin scratch test. In some cases, these are supplemented by what Fineman calls a “cautious oral challenge,” where a child eats a very small amount of the food in question in an allergist’s office, where the doctor is equipped to deal with allergic reactions. (Don’t try this at home!)

A recheck might even be in order for children with a solidly diagnosed food allergy, because many outgrow their allergies over time.
Giving allergy-free kids the all-clear to eat a regular diet is important for good nutrition, notes Fineman, who is concerned about kids who visit him “and they’ve had one blood test and been told they’re allergic to half a dozen different foods and they’re on a restricted diet.” Frequently taboo are milk and eggs. “Those are two good sources of protein that children often rely on,” he explains. “You don’t want to restrict those foods without a good diagnosis.”

To Expose or Not to Expose

Adding to concerns about the rise in food allergies are new doubts about conventional medical thinking that children are less likely to be allergic to foods such as peanuts, milk, eggs, tree nuts or seafood if they aren’t exposed to these as babies.

The Jaffe Food Allergy Institute at the Mount Sinai School of Medicine in New York is involved in some groundbreaking research aimed at preventing allergies and asthma in high-risk children – kids with allergic reactions, eczema and a family history of asthma or allergies. Researchers are studying whether exposing babies and toddlers to tiny doses of common allergens through an oral vaccine will help trigger immunity.

Institute Director Hugh Sampson, M.D., who is also the institute’s division chief of pediatric allergy and immunology, told the New Yorker recently that he and other specialists now believe early exposure could help prevent food allergies. Samson said he also believes that an estimated 80 percent of infants allergic to eggs or milk will outgrow the allergy by their teen years and that avoiding these foods may only prolong the time it takes to outgrow it.

Stay Tuned …

The initial guidelines from NIAID are meant to help healthcare providers, and they include detailed definitions of food allergies and information on how to diagnose, treat and manage food allergies in patients. A “translation” for the general public is due out this year.
Among the points stressed in the guidelines:

• Scientific evidence does not support use of a blood test called the IgG assay, which looks for a type of antibody thought to suggest a subtle type of food allergy, to make allergy diagnoses.

• Oral food challenges (the gold standard) aren’t used often enough to confirm suspected cases of food allergy.

• People of all ages with a known food allergy should have ready access to self-injectable epinephrine in case of severe allergic reaction.

• Immunotherapy treatments – where someone is exposed to small amounts of an allergen over time to build tolerance – have not yet been proven safe and effective in treating food allergies.

Meantime, if you’re pregnant or breastfeeding and trying to keep your child from developing food allergies by monitoring your own diet, the jury is still out. NIAID says there isn’t enough evidence yet to say that avoiding or eating certain foods will increase or decrease your child’s risk.

Christina Elston is a health writer and senior editor with Dominion Parenting Media. Read her blog Health-E on Parenthood. Senior Editor Deirdre Wilson also contributed to this article.


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