Peanut allergies are responsible for more deaths from anaphylaxis, or constriction of the airways, than any other food allergy. Though deaths are extremely rare, children who develop a peanut allergy generally do not outgrow it and must be vigilant to avoid peanuts for the rest of their lives.
“You have the potential to stop something in its tracks before it develops,” said Dr. Matthew Greenhawt, chairman of the American College of Allergy, Asthma and Immunology’s food allergy committee, and one of the authors of the new guidelines. It appears there “is a window of time in which the body is more likely to tolerate a food than react to it, and if you can educate the body during that window, you’re at much lower likelihood of developing an allergy to that food,” Dr. Greenhawt said.
The guidelines, published in Annals of Allergy, Asthma and Immunology and several other journals, represent an about-face from the advice given out by the American Academy of Pediatrics as recently as 2000, when parents were told to withhold peanuts from children at high risk for allergies until they were 3 years old.
Despite those recommendations, the prevalence of peanut allergies kept increasing. Ten years later, around 2 percent of children in the United States had the allergy, up from less than half of 1 percent in 1999, and the academy started retreating from its advice, which didn’t seem to be working.
The new guidelines grow out of several studies conducted in recent years that challenged the advice to ban peanuts in infancy, long a standard practice in the United Kingdom, Australia and the United States.
One report, published in 2008, was carried out by scientists intrigued by anecdotal reports that Jewish children in Israel rarely suffered from peanut allergies. Dr. Gideon Lack, the senior author of the study and a professor of pediatric allergy at King’s College London, compared the allergy rates of Israeli Jewish children with those of Jewish children in Britain, and found that British children were 10 times as likely to have peanut allergies as Israeli children, a disparity that could not be explained by difference in genetic background, socioeconomic class or tendency to develop other allergies.
One of the main differences between the two populations was that starting in infancy, Israeli children ate foods containing peanuts, often in the form of Bamba, a popular peanut-butter puffed corn snack that has the consistency of a cheese puff but is 50 percent peanuts, according to the manufacturer, Osem Group. Was it possible that early exposure to peanuts actually protected the Israeli kids from allergies?
Dr. Lack and fellow scientists tested the hypothesis in a large clinical trial in England. They recruited hundreds of infants aged 4 to 11 months, all of whom were deemed at high risk of developing a peanut allergy because they had eczema or an allergy to eggs. After running skin-prick tests on the babies and excluding those who were already allergic to peanuts, they randomly assigned some babies to be regularly fed peanut products, and others to be denied all peanut-containing foods.
By the time they turned 5, only 1.9 percent of 530 allergy-prone children who had been fed peanuts had developed an allergy, compared with 13.7 percent of the children who were denied peanuts. Among another group of 98 babies who were more sensitive to peanuts at the start of the study, 10 percent of those who were given peanuts developed an allergy, compared with 35 percent of those denied peanuts. The findings, published in The New England Journal of Medicine in 2015, “shook the foundation of the food allergy world,” Dr. Greenhawt said.
The new guidelines divide children by risk. Low-risk infants, who don’t have eczema or an egg allergy and who have started solid foods, can be introduced to peanut-containing foods around 6 months at home by their parents. So can moderate risk children, who have mild eczema.
High-risk infants, who have severe eczema or an egg allergy, should be introduced to peanut-containing foods as early as 4 to 6 months, after they start other solid foods and are evaluated by a doctor for safety.
If your baby is determined to be high-risk, the guidelines recommend an evaluation by an allergy specialist, who may order allergy testing and introduce a peanut food in the doctor’s office, Dr. Greenhawt said. Even if allergy tests show sensitivity to peanuts, the baby isn’t necessarily allergic and may benefit from eating peanut foods, he said. A baby with a stronger reaction to the skin test may already be allergic, however, and the doctor may decide to recommend complete avoidance.
One way to introduce your baby to peanuts safely is to mix a couple of teaspoons of smooth peanut butter with a couple of teaspoons of warm water and stir until it has a smooth soupy or purée-like consistency, suggested Dr. J. Andrew Bird, director of the Food Allergy Center, Children’s Medical Center at UT Southwestern Medical Center in Dallas, who wrote a paper on the subject.
One should never give a baby whole peanuts, which can be a choking hazard, and foods containing peanuts should not be the first solid a baby eats, Dr. Greenhawt said. It’s also important to continue feeding the peanut-containing food regularly, aiming for three times a week, through childhood.
He acknowledged the new recommendations may face resistance. “The nuts and bolts of getting everyone to buy in to this and trust the recommendation and the data is a big unknown,” Dr. Greenhawt said. But the potential, he says, is enormous.
“This won’t outright prevent every single case of peanut allergy – there will still be some cases – but the number could be significantly reduced by tens of thousands,” Dr. Greenhawt said. “In the best case scenario, every allergist across the U.S. could be seeing fewer cases of peanut allergy — and that’s a good problem to have.”