Peanut Allergy Symptoms: New Blood Test Cost-Efficient, Highly Accurate

A new blood test has been developed to easily identify peanut allergies in a more cost-efficient manner than other methods, scientists said. The new test is known as the Mast Activation Test.

The current oral food challenge (OFC) — a time-consuming process — involves feeding peanuts in large doses to a patient in hospital to try to confirm the allergy. This raises the risk of causing severe allergic reactions and could be harmful. However, researchers said the new test is much safer and more accurate. Skin-prick test is also used to determine peanut allergy but is also believed to be unreliable as the results are sometimes inconclusive.

“The current tests are not ideal. If we relied on them alone we’d be over-diagnosing food allergies. Only 22 percent of school-age children in the U.K. with a positive test to peanuts are actually allergic when they’re fed the food in a monitored setting,” Alexandra Santos, a Medical Research Council scientist at King’s College London, who led the study, said. “The new test is specific in confirming the diagnosis, so when it’s positive we can be very sure it means allergy. We would reduce by two-thirds the number of expensive, stressful, oral food challenges conducted, as well as saving children from experiencing allergic reactions.”

The team that conducted the study also said the test can be used to identify other food allergies. Their study, published in the Journal of Allergy and Clinical Immunology, involved 174 children aged from six months to 17 years. Of those involved in the study, 73 of them were allergic to peanuts.

Santos told the BBC that OFC test conducted in hospital in the presence of an allergist and two nurses "require access to sophisticated medical facilities needed to treat severe allergic reactions should they develop, which can be very expensive."

Peanut Allergy Symptoms

The symptoms of a food allergy, including peanut allergy, starts within seconds or minutes of eating the food. Tingling or itching in the mouth, itchy red rash, swelling of the face, mouth, throat or other parts of the body, difficulty swallowing, shortness of breath, dizziness, vomiting, abdominal pain, diarrhea, runny or congested nose and nausea are the common symptoms.

Peanut allergy is one of the most common food allergies and account for 90 percent of those suffered by 21 million Americans. According to American Academy of Allergy, Asthma, and Immunology (AAAAI), more than 3 million people in the U.S. report being allergic to peanuts, tree nuts or both. Peanut allergy is also the most common cause of food related death.

“We are adapting this test to other foods, such as milk, eggs, sesame and tree nuts. This test will be useful as we are seeing more and more children who have never been exposed to these foods because they have severe eczema or have siblings with allergies. Parents are often afraid to feed them a food that is known to cause allergic reactions,” Santos said about Mast Activation Test.