food allergy, food allergies
Stephen Morton/AP
Janet Mitchell, right, and her 4-year-old son, John Thomas, look for peanuts on the
ingredients label of snack food at their home Tuesday, Aug. 4, 2008, in Brunswick, Ga. John
Thomas has a severe peanut allergy.

Food Allergies Are Commonly Misdiagnosed

February 21, 2010 07:00 AM
by findingDulcinea Staff
Experts say blood and skin tests are not reliable in diagnosing food allergies, leaving many children needlessly avoiding particular foods.

Take a Food Challenge to Determine a Food Allergy

Dr. Leonard Bacharier, director of pediatric allergy and immunology at Washington University School of Medicine, says that food allergies are routinely misdiagnosed due to the results of blood or skin tests; experts agree that such tests aren’t reliable. 

Michele Munz explains in the St. Louis Post-Dispatch that blood tests measure the antibodies present when an allergic reaction occurs, while skin tests measure the hives that result when the skin is pricked with food extract. Due to the fact that these tests are widely available, more parents are relying on the tests to determine if their children have food allergies.

But according to Bacharier, the tests can be misleading. "In some people, these antibodies cause disease, and in other people, they don't,” he told Munz.

Food challenges are the answer but they “are labor-intensive and time-consuming,” Munz writes. Eleven doses of food are given to patients in increasing amounts every 15 minutes over a six-hour period. Though the “prospect is too daunting” for some, others find that being able to give their children peanut butter, without fear of harming them, is a huge relief.

Background: Food allergy research makes progress

A 2009 conference in Vienna, Austria, aimed to examine some of the murky issues surrounding food allergies and highlighted findings from an ongoing study looking into regional differences among allergy sufferers in Europe, Australia, India, China and Ghana. The study aimed to overcome some of the pitfalls of previous studies, many of which have relied on “self-reported” allergies rather than those that had been confirmed with tests.

Overall, the study found some promising connections between other types of allergies—pollen and dust mites, for example—and food allergies to shrimp, apples and other foods. This is due to the similarities of proteins found in these disparate allergens.

Related Topic: Nut allergy precautions

Approximately 3.3 million Americans in the United States have nut allergies, and although the allergies can be quite serious, a Harvard professor says Americans are probably going too far to protect themselves.

Dr. Nicholas Christakis, a physician and social scientist who has a child in the Massachusetts school district, questions whether precautions over nut allergies are becoming a “societal hysteria.”

Reference: Allergies

FindingDulcinea’s Web Guide to Allergies helps you learn what allergies are, how they are treated, where to find an allergy doctor and more.

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