Peanut allergy, an occasionally life-threatening condition that has prompted changes in food consumption rules everywhere from pre-schools to airlines, can be sharply reduced by feeding peanut protein to children at risk for the condition beginning when they are infants, researchers reported in a landmark study Monday.

The findings could have implications for other potentially dangerous childhood allergies, such as those to milk and eggs, and, if follow-up research shows the approach is safe, might be a response to the rapid spread of peanut allergies in the western world, experts said.

"This is really quite an important study," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, which partly funded the research. "We have been frustrated in what to do about it, and most of the tendency has been, since it's such a scary phenomenon...that parents and even pediatricians have taken the avoidance approach--keep them away from peanuts."

But in fact, the study contends, feeding small amounts of peanut protein to infants between the ages of four and 11 months who are at risk for peanut allergies dramatically reduced the incidence of the condition at the age of five, when they were compared to a group of children who did not consume peanut protein. Among the larger of two groups of children in the study, for example, 13.7 percent of those who avoided peanut protein developed the allergy while just 1.9 percent of those who consumed it did.

The research was published in the New England Journal of Medicine. An accompanying editorial described the research as  a "landmark study," called for quick issuance of new guidelines on peanut consumption by children and recommended that some infants between the ages of four and eight months who are at risk for the allergy be started on small amounts of peanut protein.

One of the lead researchers, Gideon Lack, head of the Department of Pediatric Allergy at King's College London, agreed. "I believe that the findings are robust enough to tell us that if a child is at risk for peanut allergy...that child should immediately, as soon as they develop the first signs, have a skin prick test" for the allergy, he said. If the test is negative, the child "should be encouraged to eat peanuts regularly," Lack said.

If the skin test is positive, the same program could be followed under the supervision of a pediatrician, he said.

For some people who are allergic to them, peanuts can cause a severe, sometimes rapid whole-body reaction called anaphylaxis that includes constriction of the airways that can be life-threatening. Such people must be extremely careful about consuming even trace amounts of peanuts and may have to carry injectable epinephrine with them to counter the effects of a reaction.

Milder symptoms of the allergy can include hives or other types of skin rash, digestive problems and shortness of breath or wheezing.

According to the editorial, the prevalence of peanut allergy has quadrupled in the United States in the past 13 years, from 0.4 percent in 1997 to 2 percent in 2010.

Separately, a study presented at a conference Sunday showed that wearing a skin patch containing 50 to 250 micrograms of peanut protein appeared to protect people with peanut allergies against the dangerous reactions of the condition.

A growing number of schools are updating their peanut butter policies in response to the rise in peanut allergies among children. The Post asked the experts to sample a few alternative spreads. (Davin Coburn, Jason Aldag, Randolph Smith and Kate Tobey/The Washington Post)

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