WASHINGTON — Parents of kids with food allergies live with a lot of uncertainty, but a new test might just give them some much-needed answers.
Current testing can only determine whether someone is allergic to a specific food — not the full extent of the danger posed by that allergy.
“We have such a black hole with food allergy, because there is such a sense of the unknown,” says Dr. Rachel Schreiber, an allergist in Rockville, Maryland.
She says the new test would fill that gap by allowing doctors to predict the severity of an allergic reaction and provide some peace of mind for worried parents.
“One of the biggest questions that we get is, ‘Well, what will happen to my child?’” she says, adding that this test will be an important addition to the allergist’s tool kit.
Currently, doctors base their diagnoses on clinical histories, scratch tests, blood work and sometimes what is referred to as an oral challenge — administering a tiny amount of the suspect food to a patient under medical supervision.
That testing is usually stopped at the first sign of trouble, but that means doctors do not get a read on the full extent of the allergic reaction.
The test under development is designed to provide that information easily and safely by measuring levels of a specific type of immune cell in the blood. Those cells are activated when a person is exposed to a food that sets off an allergy.
The immune cell measured is the basophil, and the basophil activation test requires only a small blood sample and produces quick results.
Researchers at Mt. Sinai Medical School, in New York, tried it on 67 patients and were pleased with the results. Their study — published online in The Annals of Allergy, Asthma and Immunology — endorses the test, saying it provides accurate information in a safe manner.
“It is not really ready for prime time yet,” says Schreiber, noting that more studies are needed. But she says that once this test is adopted as part of the testing regime, patients, parents and physicians will get vital information.
She does not envision its use as part of a standard screening for allergies; rather, a way to take a kid already diagnosed with a specific food allergy and determine the dangers that may lie ahead.
