Fighting Food Allergies
For individuals with an allergy to peanuts, accidental ingestion can produce a severe reaction. A new study is looking a whether giving tiny doses of peanut protein can desensitize the body and prevent future reactions. If successful, researchers may try this approach with other foods that produce allergic reactions.
For more than a million people in the U.S., taking a bite of food containing even a trace of peanuts can be a life-threatening experience. The allergic reaction can cause severe respiratory problems and even death.
"What happens is that you have a systemic reaction, one that occurs all over the body," explains Wesley Burks, chief of the Division of Allergy and Immunology in the Department of Pediatrics at Duke University Medical Center.
"It's a typical allergic reaction. It can involve the gastrointestinal tract, with vomiting and diarrhea. It can involve the skin, with hives and whelps and angioedema, or swelling. It can also involve the respiratory tract, which would mean coughing, wheezing or swelling of the throat. Those three systems are a combination of the allergic response you'll see."
Food allergies are more common in young children than in older children or adults, occurring in between six and eight percent of preschoolers. By school age the figure drops to approximately five percent. Between three and four percent of adults are affected. Three foods -- milk, eggs and peanuts – cause almost 80 percent of all reactions.
The only treatment at this time, once symptoms appear after an accidental ingestion, is taking an antihistamine and then epinephrine, to relieve shortness of breath.
Burks is currently leading a study at Duke which is looking at a possible new method for fighting peanut allergy in children. He said the treatment approach being used in the study, called allergen immunotherapy, is much the same as using antivenom to gradually desensitize the body to bee stings, which can help prevent future allergic reactions.
"What we're doing is to take small amounts of peanut protein and gradually giving increasing amounts over an initial day and then over a period of three-and-a-half to four months. Every other week, we give them a larger dose," explains Burks. "At the end of that period, they're getting about 300 milligrams of peanut protein, which is the equivalent of one peanut."
"What we're finding is that they're less sensitive when they eat a peanut accidentally, so that they're not having the same reaction they did before. What we're hoping to find at the end of this study is that they've actually 'outgrown' their peanut allergy."
Burks said early results are encouraging and believes the same approach may work with other food allergies. "If we can find a safe and effective way to do it, there's nothing specific about the peanut that we couldn't do it with other foods like milk, eggs and tree nuts."
We hope to publish the initial findings in the next six months," he adds. "Early indications are that this approach does work."