Peanut M&M dispensers stand in the waiting room of the New England Food Allergy Treatment Center. The children coming to the center are openly flouting rules drilled into their heads for most of their lives : Avoid peanuts and potentially contaminated products at all costs. Instead, the children here eat carefully measured doses of peanut protein , usually mixed into yogurt, pudding or apple sauce , in a treatment known as oral immunotherapy. The idea is to gradually increase the doses to desensitize their bodies to peanuts so they no longer suffer allergic reactions. "We've treated about 750 to 760 patients so far with a 90 to 92% success rate," says Jeffrey Factor, fouder and medical director of the center , which opened in 2010. Nearly all the patients, most of whom are children , come because of peanut allergies. Oral immunotherapy , often called OIT , isn't approved by the U.S. Food and Drug Administration or endorsed by any professional organization of allergists. Some of the country's leading allergists say that , despite promising evidence, more research and regulatory approval are needed before the process should be recommended as a treatment for food allergies. Studies have shown about 80% to 85% of patients who undergo oral immunotherapy are successfully desensitized to their allergen. But questions remain about its long-term effectiveness, and there are concerns some patients could have adverse reactions, these allergists say. "We absolutely don't do OIT for treatment," said Robert Wood, division chief for pediatric allergy and immunology at Johns Hopkins School of Medicine, in Baltimore, which is participating in about a dozen OIT trials for different foods. "In my mind doing so is pushing the envelope beyond the appropriate level of safety , " Dr. Wood says. Peanut allergies are the most common and dangerous, with reactions ranging from skin rashes to anaphylactic shock, which can be fatal. About 80% of children don't outgrow peanut allergies. There is no approved treatment for food allergies except avoidance. There is no uniform protocol for OIT for food allergies, which is a reason critics say it shouldn't be recommended for treatment. Whether the treatment lasts is the subject of research by some prominent allergists.