New findings about peanut allergies is turning the advice pediatricians give to parents of young children on its head. Scientists from North Carolina are in the thick of this new research.
By Whitney L.J. Howell
As a 15-month-old, Brayden Baylor touched his first peanut butter cracker. Within minutes, his face turned red, he broke out in hives and he began rubbing his eyes until they were swollen shut.
It was a classic peanut-allergy reaction. But, because he hadn’t actually eaten the cracker, or the peanut butter on it, his parents didn’t realize what was happening – until a second reaction erupted within hours.
“We had given him a dose of Benadryl, and, at the time, we still didn’t really know what caused the problem. There’s no history of food allergies in either of our families,” said Karrie Baylor, Brayden’s mother and a Charlotte resident. “But when it happened a second time, he was sitting in my lap and suddenly turned red and swollen. That’s when we took him to the emergency room.”
After a blood test, a local allergist diagnosed Brayden with a peanut allergy – a potentially deadly immune response affecting between three million and six million Americans, the majority of whom are children. According to a 2001 Archives of Internal Medicine study on food allergies, peanut allergies rank worst, accounting for more than 50 percent of the 200 annual food allergy-related deaths nationwide.
In fact, the fear of peanut allergy and its potentially fatal outcomes prompted the American Academy of Pediatrics, in 2000, to issue guidelines recommending children consume no peanut protein before age 3. The hope was that delayed exposure would give a child’s immune system time to strengthen and prevent peanut allergies.
But that hasn’t happened. Between 1997 and 2010, peanut-allergy prevalence among American children has skyrocketed 50 percent, according to the Centers for Disease Control and Prevention. And, based on existing data, occurrence within North Carolina mimics the national population.
This meteoric rise has baffled allergy and immunology researchers and sparked many investigations into the body’s response to peanut protein and how it can be calmed. Now there’s a watershed study, funded by the National Institutes of Health, that experts say conclusively proves the existing approach to combating peanut allergies has been wrong.
In short, the AAP guidelines meant to safeguard children like Brayden are actually causing more allergy cases to break out.
“This study is definitive. That’s unusual in this business,” said Herman Mitchell, vice president for Rho, the Chapel Hill-based contract research organization that handled the study’s statistical and data coordination. “We usually see trends, but this is a whopping finding that is very clear. It’s a reason to completely change the recommendations about avoiding peanuts at an early age.”
While peanut-allergy rates are high in the United States and United Kingdom, that’s not the case everywhere. A 2008 Journal of Allergy and Clinical Immunology study revealed British children were 10 times more likely to have a peanut allergy than Israeli children.
Those nation’s health care systems are roughly equivalent, but there’s a significant cultural difference. Israeli families introduce children to peanut products far earlier. A snack called Bamba – a peanut butter-flavored corn puff – is present in 90 percent of Israeli homes and helps transition infants to solid food.
As part of the NIH’s Immune Tolerance Network, Gideon Lack, pediatric allergy professor at King’s College London, launched a study to investigate whether eating peanut-protein products, such as Bamba, early has a protective effect, Mitchell said.
Lack’s five-year study enrolled 600 4-to-11-month-old children who were at risk for developing a peanut allergy.
They either had another existing food allergy, a family history of peanut allergy or eczema. Half of the children were introduced to Bamba, while the other half followed the existing guidelines that prohibit exposure. The children who received Bamba ate it three times a week for five years.
The study ended with a food challenge that escalated the peanut-protein amount participants ate over several hours.
The results, published in a February New England Journal of Medicine issue, showed children who ate Bamba were 81 percent less likely to develop peanut allergy. Among non-consumption participants, 13.7 percent developed a peanut allergy, while only 1.9 percent of the Bamba group did.
According to Wesley Burks, chair of pediatrics at the UNC-Chapel Hill School of Medicine, Lack’s study will change how doctors advise parents about peanuts.
Burks leads a long-standing peanut-allergy study designed to help children with existing peanut allergies, including Brayden, develop a tolerance to peanut protein.
“These studies will change the paradigm with respect to feeding in the first six months of life for kids with allergic diseases. The guidelines for introducing peanut protein will change within the next year,” he said. “That will be the easy part; but medical guidelines take years to be disseminated.”
It will take between five and 10 years, he said, for pediatricians to abandon the current guidelines and begin advising parents based on these new findings.
Testing the idea
While the results of Lack’s study seem to indicate that preventing peanut allergy before it occurs is possible, it’s not yet clear whether that’s the case, Mitchell said. The effect could be desensitization, meaning participants who exhibit no current allergic responses could have reactions to peanut protein later in life.
To answer that question, several Bamba group participants agreed to avoid peanut protein for a year and then complete another food challenge. This new group will also include 40 children who don’t have peanut-allergy risk factors but had a positive allergy skin test. Results of this new study will also help doctors treat children with peanut allergies.
“It would be ideal if we could understand exactly who’s at risk,” he said. “Then pediatricians could measure a child’s risk and could recommend early [peanut-protein] exposure.”
Mitchell advised that parents have their child evaluated by an allergist if any peanut-allergy risk factor exists. An allergist can provide guidance on how to introduce peanut protein into the diet.
These study results and new guidelines will help prevent peanut allergies in infants and newborns, but it can’t help the children who already live with peanut intolerance.
That’s where Burks’ work comes in. For more than 25 years, he has worked toward treatments that help children – most of whom are over age 2 – develop a peanut-protein tolerance that reduces the severity of allergic reaction. The therapy is considered a success if a child can ingest a peanut or peanut protein without being thrown into a debilitating or potentially fatal immune response.
To date, Burks, who is also physician in chief at North Carolina Children’s Hospital, and his team have developed three treatment forms, all of which culminate with a food challenge similar to Lack’s study. In some cases, participants drip peanut protein-infused liquid under their tongue, while others wear patches impregnated with peanut protein. The most effective strategy though has been mixing peanut-protein powder with other well-tolerated foods, such as applesauce or ice cream.
“When the protein powder is introduced regularly – and in increasing quantities – it can make changes to the immune system,” Burks said.
Based on Rho’s data, Burks said he will begin to enroll and treat younger children in a continued effort to reduce peanut-allergy impact.
In the meantime though, he will continue to treat children Brayden’s age and younger, helping them overcome their peanut allergies. Brayden’s therapy has already been declared a success after three years: He passed his final food challenge without exhibiting any signs of allergic reaction.
His celebratory feast? His first-ever Reese’s Peanut Butter Cup.