Food Allergy Tests Not Always Accurate

By Heather Legg

We often wonder why some many children have food allergies. I’ve often had the conversation that “When I was in school, there weren’t this many allergies…” So why? There is the theory of our overly hygienic society, that mothers to be eat too many of certain foods causing allergies, that babies are given things too early, too late… Well what about over diagnosis?

According to an article this past weekend in Ajc.com (http://www.ajc.com/health/content/health/stories/2009/02/03/food_allergies_false_signs.html),

“Doctors say misdiagnosed food allergies appear to be on the rise, and countless families are needlessly avoiding certain foods and spending hundreds of dollars on costly nonallergenic supplements. In extreme cases, misdiagnosed allergies have put children at risk for malnutrition.”

Again, the question is why? According to the same article:

“The culprit appears to be the widespread use of simple blood tests for antibodies that could signal a reaction to food. The tests have emerged as a quick, convenient alternative to uncomfortable skin testing and time-consuming “food challenge” tests, which measure a child’s reaction to eating certain foods under a doctor’s supervision.

While the blood tests can help doctors identify potentially risky foods, they aren’t always reliable. A 2007 issue of The Annals of Asthma, Allergy & Immunology reported on research at Johns Hopkins Children’s Center, finding that blood allergy tests could both under- and overestimate the body’s immune response. A 2003 report in Pediatrics said a positive result on a blood allergy test correlated with a real-world food allergy in fewer than half the cases.

“The only true test of whether you’re allergic to a food or not is whether you can eat it and not react to it,” said Dr. David Fleischer, an assistant professor of pediatrics at National Jewish Health.”

I know our alternative practitioner told me that scratch allergy tests are often unreliable for food allergies. She said that after completing NAET treatment, the scratch test could still show positive for allergies, but if the patient ingested the food he or she would be fine. Often times, too, the child has really outgrown the allergy, but it still shows positive. We have never retested our daughter, though she has not had a reaction in over 4 years. We are careful and don’t let her eat nuts, but do let her eat the foods processed ons hared equipment, etc.

“Dr. Nicholas A. Christakis, a professor at Harvard Medical School, argues that an “overreaction” to allergy is leading to unnecessary testing and false positives.“If the kid has been doing fine, I would advise parents not to get allergy testing, because the results are more likely to be false positives than true positives,” Christakis said in an interview. “If they do think they need allergy testing, be extremely measured and go to reputable people.”

So do our children have more allergies, or do are we the ones who are “overreactive?”

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