Edmond Chan’s campaign to change a mistaken medical mindset – and reduce peanut allergies
For all of the lives saved, extended or improved by medical progress over the past few decades, it also has brought a few high-profile reversals: hormone therapy for post-menopausal women (first promoted for its supposed cardiovascular benefits, then abandoned due to harmful side effects); stenting for stable coronary artery disease (also promoted, then deemed unnecessary); the utility of mouth-to-mouth artificial resuscitation (now considered an unnecessary diversion in most cases from more important chest compressions); and substantial changes in what is considered a healthy diet (fats, at least certain kinds, are making a comeback).
One of the more dramatic about-faces from the medical community has been advice about kids and peanuts. Starting around 2000, the official advice to parents from the American Academy of Pediatrics was to delay introducing peanuts to children “at risk for allergy” until they are 3 years old – a message that was then informally interpreted to apply to all children. And then, starting in 2007, the medical establishment began to reconsider.
Edmond Chan, who became a pediatric allergist during that period, has dedicated himself to correcting that mistake – not just in his own practice, but among physicians. And it has not been easy.
“This 180-degree turn makes physicians and patients uncomfortable,” says Dr. Chan, the Head of the Division of Allergy and Immunology in the UBC Department of Pediatrics. “They’re just waiting for it to swing back again.”
Even as Dr. Chan labours to spread the word, he has done research showing that health professionals aren’t hearing it.
“It’s frustrating, but understandable,” he says. “It’s hard to reach that audience because they’re so busy seeing patients. It’s a slow process.”
A lone Canadian voice on U.S. panel
But Dr. Chan, a Clinical Associate Professor, Director of the Allergy Clinic at BC Children’s Hospital and a Clinical Investigator at the Child and Family Research Institute, soldiers on, speaking at conferences, drafting communiques, publishing his own articles – including one recent case study, published in the Journal of Allergy and Clinical Immunology: In Practice in March 2016, describing a difficult case inspired by a child in his own practice.
He is the only Canadian member (and one of only two non-Americans) sitting on a U.S. National Institutes of Health (NIH) expert panel that addressed the problem by issuing an official recommendation. The guidelines, which will be more detailed than previous communiques from professional organizations, were released Jan. 5, 2017.
“To be part of this panel, and to rub shoulders with some of the most respected names in the field, has been such a privilege,” he says. “I’ve learned a lot by going through this process.”
As a resident and fellow in Winnipeg, the “avoid peanuts until age three” mantra was drilled into him, and he in turn repeated it to his patients, both there and at BC Children’s Hospital, where he began practicing independently in 2005.
But he quickly took notice when contrary studies were published – including a 2008 study that compared Jewish children in the U.K. with Jewish children in Israel, where peanuts are typically part of an infant’s diet. The authors found that the incidence of peanut allergies among the Israeli children was 10 times lower than among the British children.
“I was a bit perplexed, and looking for clarity on the issue,” Dr. Chan says. “I was constantly talking to colleagues and reading the literature. It became a hot topic for discussion at meetings.”
Spreading the word
Things became clearer, at least for Dr. Chan, in 2008, when the American Academy of Pediatrics – the same group that in 2000 advised delaying peanuts until age three – reversed itself, saying there was no convincing evidence to avoid peanuts beyond four to six months of age, which is when solid foods would normally be introduced to an infant’s diet.
Dr. Chan pivoted, but he knew that this new-found knowledge was not percolating to the people who really needed to hear it – the pediatricians and family practitioners who care for the vast majority of infants.
His first effort to spread the word was through “This Changed My Practice,” an online forum of the Faculty of Medicine’s Continuing Professional Development office. Like other postings on that site, his was something of a confessional, divided into three parts: “What I did before,” “What changed my practice,” and “What I do now.” He not only explained that there was no reason to delay; he went further, saying that future research might show that introducing it by four to six months might prevent peanut allergy.
But his fear that the latest advice wasn’t being adopted continued to nag at him. So he undertook a study of general pediatricians and dieticians in B.C., with a resident research grant from the UBC Department of Pediatrics. The findings, published in the journal Allergy, Asthma and & Clinical Immunology in 2012, showed that nearly half of pediatricians recommend delaying peanut foods, compared to 31 per cent of dieticians.
He was also a co-author of a similar study in Atlantic Canada, which found an even higher proportion of pediatricians and dieticians recommending delaying peanuts until at least a child’s first birthday.
“That formed the basis for our concern that the message wasn’t getting to Canadian practitioners, or that the message was getting to them but they were still hesitant to change course,” Dr. Chan says.
Walking the line
So Dr. Chan, through the Canadian Pediatric Society and the Canadian Society of Allergy and Clinical Immunology, joined with colleagues to draw up a message specifically targeting Canadian health providers. Published in 2013, those guidelines went beyond the American Academy of Pediatrics by saying that introduction of peanuts later than six months of age may actually increase the risk of peanut allergy, and that once introduced, peanut should be given regularly (ideally, several times a week) to maintain tolerance. It also discouraged routine allergy testing before the first contact with the food, because of the high probability of a false positive.
Dr. Chan, along with Pediatrics Professor Ran Goldman and then-pediatrics resident (now a fellow in pediatric emergency medicine) Benetta Chin, followed that up a few months later with an article in Canadian Family Physician, reiterating the new Canadian guidelines in a more succinct style, tailored to busy family practitioners.
Still, the guidelines “walked the line,” as Dr. Chan describes it — saying there was no benefit to delay but not taking the next step of saying peanuts should actively be introduced.
Then, in February 2015, new evidence emerged in the New England Journal of Medicine: a randomized study in the U.K. found that early introduction of peanuts in high-risk infants with severe eczema or egg allergy (between four and ten months of age) led to an over 80 per cent relative risk reduction in developing peanut allergy by age five. Finally, this was the “Level I” evidence that was needed for a stronger message about early peanut introduction.
Why is earlier better? The current theory is that immune cells in the digestive tract are better able to accept peanut protein and become tolerant of its presence. If not exposed that way, children might get their first exposure through “broken” skin (most children who develop peanut allergy have eczema first), through incidental contact with a parent or sibling who has been eating peanuts. Skin immune cells might be more likely to “overreact,” priming the body to treat peanut protein as a foreign invader.
“It’s not just fear”
Regardless of the physiological mechanism, the solid evidence from the U.K. led a global group of experts, including Dr. Chan, to publish a “consensus communication” – recommending early introduction of peanuts – published in seven journals in the summer of 2015. This statement finally went the extra step of saying that peanut should be introduced early in high-risk infants.
The NIH task force guidelines, released in Jan. 2017 through the National Institute of Allergy and Infectious Diseases, reinforce that message, carrying with it the imprimatur of a government communique – and, Dr. Chan hopes, spreading beyond the limited orbit of academic journals and professional societies.
“Changing people’s minds about this is so difficult, because there’s this fear,” says Dr. Chan, who will be speaking about this topic at the Canadian Paediatric Society’s annual conference in June and a variety of other medical conferences. “We have drilled into people’s minds that a peanut allergy can be a life-threatening condition, yet on the flip side, no infant has died from trying peanuts for the very first time in the first few months of life.
“But it’s not just fear. Our message is also more complex. It’s easier to just avoid peanuts than to think about what kind of non-choking peanut product is best for an infant, the amount needed, or how frequently and for how long it should be given. How do you make it simple for parents, who are so busy with other decisions for their infant?”