Everybody likes a free lunch. And everybody who pays for health care in America likes a free health screening, so when the Giant Eagle grocery chain started offering free in-store allergy tests, lots of people accepted the offer.
As discussed on HealthNewsReview.org by Kevin Lomangino, editor-in-chief of Clinical Nutrition Insight, allergies are like prostate cancer and breast cancer. They are a public health problem that you simply can’t test your way out of, at least based on current knowledge.
It’s important to detect and treat food and other allergies – they can be life-threatening. But as Lomangino says, “indiscriminate testing for allergies may be even worse than not enough testing.”
Dr. Richard Wasserman, an allergist in Dallas, told Lomangino that allergy test panels are being heavily marketed to doctors as a means to boost practice revenue. Never mind that such tests have been shown to generate a false-positive as much as half the time when used to detect food allergies. Wasserman said that many patients probably are being tested in situations in which a careful clinical history would rule out suspected food allergy.
As an allergist, Wasserman acknowledges that he might be biased against primary care docs conducting allergy testing. But his concerns about the overuse of food allergy tests are supported by guidelines from the National Institutes of health (NIH) about food allergies. Lab tests are frequently (and incorrectly) used as the sole basis for a food allergy diagnosis.
Which brings us back to the “Attention Shoppers! Free Allergy Testing On Aisle 2!” approach to health care.
Because so many tests indicate a positive result when there is no allergy, their subjects will avoid foods unnecessarily. These diagnoses require a more careful evaluation.
Wasserman offered a hypothetical Giant Eagle customer with nasal symptoms who received a false-positive test for allergy to ragweed. That person might start taking Allegra in the mistaken belief that it would reduce symptoms. But an expert clinical evaluation might have turned up a more serious ailment whose discovery was delayed because of the false test result. Or that person might experience a side effect of Allegra worse than the symptoms of the nonallergy.
“A positive test does not equal a diagnosis, which is the premise of the testing programs,” Wasserman said. “These tests are fundamentally useless without a formal evaluation of the patient.”
The NIH guidelines indicate a growing awareness of false, easy-fix allergy diagnoses, but Lomangino says we’re still a long way from implementing an evidence-based standard for allergy testing. One study showed that in 103 out of 111 children who were avoiding foods based on allergy test results had no reaction to the food when they ate it during a carefully conducted food challenge.
Such false diagnoses are disruptive. Special diets can be difficult to follow and restrictive diets can be more expensive. People can suffer unnecessary anxiety about accidentally eating the “wrong” thing.
So if you’re having symptoms of what you suspect is an allergy — to food, to dust, to plants … whatever — don’t seek confirmation at the same establishment where you’re buying razor blades and Cheez-Whiz. And if your primary care provider gives you an allergy test that’s positive, before embarking on treatment, ask for a second opinion from a board-certified allergist.
Repeat after me: There’s no free lunch. Ever.
Article first published as The No-Free-Lunch Lesson in “Free” Allergy Testing on Technorati.