Tuesday, October 20, 2015

Why so many kids today have food allergies? Maybe our tests are the problem

Perhaps one reason why there are far more children today diagnosed with food allergies, especially peanut allergies, is that they have symptoms of another ailment, are then tested for food allergies, and they test positively, but it is a poor test.

This is exactly what happened in Dallas to “a 15-month-old girl—her stomach, arms and legs swollen and her hands and feet crusted in weeping, yellow scales.” She “was rushed to the emergency room at the University of Texas Southwestern Medical Center in Dallas.”

When eliminating the foods the child had tested allergic to did not clear up her illness, a more sophisticated test was employed. And it showed the girl did not have any food allergies.

“To her mother's astonishment, the toddler showed no adverse reaction to any of them. After a few days of steady nourishment and a course of antibiotics to clear her skin of various infections, she was released from the hospital into a life free of food restrictions.”

According to this piece in Scientific American, the problem is with false positives in the most-used food allergy tests:

Common skin-prick tests, in which a person is scratched by a needle coated with proteins from a suspect food, produce signs of irritation 50 to 60 percent of the time even when the person is not actually allergic. “When you apply the wrong test, as was the case here, you end up with false positives,” says pediatric allergist J. Andrew Bird, who co-authored a paper describing the Dallas case in 2013 in the journal Pediatrics. And you end up with a lot of people scared to eat foods that would do them no harm. Bird has said that he and a team of researchers found that 112 of 126 children who were diagnosed with multiple food allergies tolerated at least one of the foods they were cautioned might kill them.

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