Researchers say feeding children small amounts of peanut protein every day reduced allergic reactions. (Brad Farris/Associated Press)
Tiny doses may help peanut-allergic kids

For some children, even trace amounts of peanuts can be deadly. But these kids have no options other than to avoid the legumes completely. The results of a new clinical trial may change that. Scientists have found that feeding allergic children small amounts of peanut protein every day can help them lead a normal life.

“This is a very important first step,” says Gideon Lack, a pediatric allergist at King’s College London, who was not involved in the work. “But I don’t think it is ready to go into clinical practice.”

About 1 percent of children in high-income countries such as the United States and the United Kingdom have a peanut allergy. Their immune system reacts to proteins found in the nuts, and in severe cases that reaction can cut off breathing or lead to a sudden drop in blood pressure, starving the organs of oxygen. The condition puts a lot of stress on families, because even children who have reacted mildly to peanuts in the past can suddenly have a life-threatening incident, says a pediatric allergist Andrew Clark, one of the researchers involved in the trial.

Some studies have shown that exposing children to increasing doses of peanuts can desensitize them, but few big trials have been done. Some studies in the 1990s tried injecting the antigen into the skin. But side effects were severe, and in one study a patient died because of a dosing error. “Because of that, people haven’t touched this for 10, 20 years and are only now approaching it again,” Clark says.

Clark and colleagues started with 49 allergic children age 7 to 16. The kids’ meals included a small amount of peanut flour, with the dose slowly increasing from two milligrams to 800 milligrams (equivalent to about five peanuts). A control group of 46 children who had a peanut allergy avoided the nuts altogether. After six months, 24 of the 39 children in the treatment group who completed the study could tolerate 1,400 milligrams of peanut protein without showing a reaction, but no one in the control group could, the authors report in the Lancet.

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