Gradual peanut exposure shows promise as an allergy treatment: study shows some children can overcome their symptoms.

WASHINGTON -- Very gradual introduction of peanuts into the diet--starting with less than 1/1,000th of a peanut a day--may prevent allergic reactions to peanuts in some children, a new study finds. But the bit-by-bit strategy takes time and may not work in everyone, researchers reported March 15 at a meeting of the American Academy of Allergy, Asthma & Immunology.

In the longest study of its kind to date, the strategy of adding slightly more and more peanuts to a child's diet each day has enabled five children once allergic to peanuts to eat peanuts and peanut butter at will, says study coauthor Wesley Burks, a pediatric allergist and immunologist at Duke University Medical Center in Durham, N.C.

Burks and his Duke colleagues teamed with scientists at the Arkansas Children's Hospital Research Institute in Little Rock to study 29 children who were allergic to peanuts. Each child initially received only microscopic amounts of peanut in a solution given at a research center.

After a few days, the children started getting tiny but ever-increasing amounts of carefully measured peanut powder at home, mainly sprinkled on their food. At the start of the study, the kids were 5 years old on average.

After eight months, some of the volunteers were able to eat 13 to 15 peanuts without having any allergic symptoms.

Nine of the children have been involved in the study for more than two years, and five of those nine appear to be free of peanut allergy even though they are no longer getting the treatment, Burks says. "They are putting peanuts in their diet," he says.

The other four from this initial group of nine have been slower to benefit from the gradual exposure, possibly because they had a stronger allergy to begin with, he says.

Data from the other participants will be available in coming months.

The two teams have begun a second allergy study in which five children receive this gradual peanut treatment and five others get a placebo. After one year, early results show protection in the treated children. This study is needed to help determine whether the strategy works.

"These are preliminary, small studies that are not yet giving us a final answer on the best treatment methods," says Robert Wood, a pediatric allergist at Johns Hopkins University in Baltimore. He thinks the approach holds promise, but he predicts that a daily treatment similar to this one might still be 10 years off.

This treatment was actually tried more than a hundred years ago but was set aside, says Scott Sicherer, a pediatric allergist at Mount Sinai School of Medicine in New York City. The new studies raise many questions, he says.

"Have we really cured the allergy, or are [the patients] just desensitized while they are getting the treatment?" he asks.

Nevertheless, the burden that a food allergy places on a family makes this treatment worth pursuing under scientific supervision, Sicherer says. "This is very encouraging, but it's not something you try at home."