As parents of children who've experienced an allergic reaction know, it can be difficult to determine exactly what is going on in your son's or daughter's body and what it means for you all going forward. Now, a new report from two leading allergists tries to cut through that confusion, warning that the most common allergy tests should not be used as a crutch by doctors and should never serve as the sole means of diagnosing an allergy.
In the article, published Monday in the journal Pediatrics, Dr. Robert Wood of the Johns Hopkins Children's Center and Dr. Scott Sicherer of Mt. Sinai caution that while blood and skin tests can pick up sensitivity to a substance, they stop short of accurately determining whether or not a child has a full-blown allergy.
Both blood and skin tests detect the presence of particular antibodies released by the body in the face of a potential allergen. Skin testing can include a skin-prick test, where a small amount of the suspected allergen is placed on the skin and then pricking the spot so it moves under the skin, as well as the patch test, which entails taping an allergen to the skin for 48 hours.
As evidence of the potential for over-diagnosis, the researchers cite data from the 2005-2006 National Health and Nutrition Examination Survey suggesting that 8 percent of the participants tested positive for peanut allergy, but only 1 percent were actually clinically allergic.
"There is a lot of confusion as to the best way to use and interpret these tests," Wood told The Huffington Post. "However, these recommendations should be welcome -- to help with the confusion -- and not contentious."
Indeed, the researchers offer several guidelines for improving testing and diagnosis.
If doctors suspect a food allergy, patients should try so-called "food challenge" tests, in which they eat certain foods under a physician's supervision. Skin and blood tests should be used only to confirm a suspected allergic trigger after symptoms have been seen, but never as general screens to look for allergies in kids without symptoms.
"We tend to think of medical tests as providing a clear yes or no answer, but with allergy testing, it’s not that simple," said Jennifer Jobrack, midwest director of philanthropy at the nonprofit Food Allergy Initiative and mother to a food-allergic son, Eli.
"Research shows that oral food challenges conducted under proper medical supervision really are the gold standard for diagnosing food allergies," she continued. "But many parents may not be aware this kind of testing is an option."
Jobrack said that when her son was diagnosed with food allergies, she tried to learn as much as possible about treatment options and knows many others do the same. She encouraged parents to educate themselves about the allergy testing options out there as well.
The authors of the new report also suggest that pediatricians and primary care providers seek outside help as needed. They should be prepared to consult with allergist-immunologists with specialized expertise who can help determine whether or not a clinical allergy actually exists and how severe it is. Wood explained that for food allergies, severity can be determined from the history of reactions, as well as through food challenges; for allergies like hay fever, asthma and cat or dog, history is the only way to gauge severity.
"The bottom line is that, while allergy tests can be a valuable tool, pediatricians should use them cautiously and judiciously and interpret results in the context of symptoms and history," Wood said.
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