Alexa Druyanoff, Contributing Reporter

Introduce peanuts to a young child and their chance of developing a peanut allergy later in life goes down by 80 percent. 

That’s the strategy underpinning the new Pediatric Food Allergy Prevention Program at Yale New Haven Children’s Hospital. Heading the program are pediatric allergists Stephanie Leeds and Julie Flom. The two recommend early exposure to allergens, especially for children with eczema, with the aim of preventing the development of food allergies. In the meantime, children can use treatments such as that eczema cream for toddlers.

“We often see patients where we feel like there might have been an opportunity to prevent food allergy, or might be opportunities going forward,” Flom said. “So the idea of being able to apply this research to our populations and make a difference is exciting.”

Their program was launched this fall and is currently operating through internal referrals from pediatricians at Yale. They are collaborating with food allergy dietician Julia Munoz, working directly with families to curate an infant’s diet to manage or prevent allergies. 

In recent decades, there have been increases in the number of children diagnosed with food allergies, the number of common food allergens, the frequency of allergy-related emergency room visits and the severity of allergic reactions. 

Rather than treating allergies, Leeds and Flom hope to prevent them entirely.

The two main reasons why a patient would be referred to this program include a strong family history of allergies or a history of eczema. In particular, the doctors singled out severe eczema as the biggest risk factor for the development of allergies. 

“Exposure [to allergens] through skin before the gut promotes allergic sensitization rather than tolerance,” Leeds said. “So the idea is to bypass that and get the food in early through the gut so that you develop a normal immune response to the food.”

The dual allergen hypothesis states that sensitization to allergens happens through skin. As the biggest immune organ, the skin serves as the body’s first barrier of defense. However in cases of severe eczema — a “defect in the skin barrier” — environmental agents like allergens are able to break into the skin.

When immune cells in the skin “see” the allergen, they may perceive the allergen as a problem, Flom said, but if the allergen is ingested through the gut first, the body is more likely to learn how to tolerate it.

“We’re definitely going to be following the literature to think about later ages, but right now, we’re focused on that first year, when foods are first being introduced into the diet,” Flom said.

This idea is supported by the groundbreaking LEAP study from King’s College. In the study, the authors followed 640 infants with either eczema or a severe egg allergy — or in some cases, both. Half of the infants were assigned to avoid peanuts until 5 years of age, while the others had peanuts introduced into their diets earlier. 

The infants who were introduced to peanuts before 5 years had a 1.9 percent chance of developing a peanut allergy, while the other group had a 13.7 percent chance of developing a peanut allergy. 

Before the LEAP study, the World Allergy Organization’s recommendation was to delay introduction of allergenic foods until kids were a few years old. The LEAP trial inspired a paradigm shift, providing evidence for the superiority of early introduction. To translate this research into actual clinical practice, pediatricians are typically on the frontlines, discussing both knowledge and risks with patients.

“As allergists, we all are aware of the updated guidelines about early introduction, but we sort of felt like we wanted to create a clinical initiative that would bridge knowledge gaps for both pediatricians and the community at large,” Leeds said.

Leeds had previously worked with pediatricians in the Extension for Community Health Outcomes program, focusing on food allergy management and prevention. She emphasized the importance of partnering with pediatricians, who are the entry point for helping parents with early feeding and dieting for their children.

Munoz, a registered dietitian affiliated with the program, joined the Yale New Haven Hospital Pediatric Allergy team in 2020. Munoz said she has always had an interest in nutritional considerations for disease prevention and found this program to be a rewarding experience.

“There is a tremendous amount of fear and misinformation surrounding infant feeding and food allergies, even within my own professional sphere,” Munoz wrote in an email to the News. “I am grateful to be able to present evidence-based recommendations to my peers, patients and their caregivers.” 

Munoz’s clients within this program typically fall into two categories: pregnant people or families with young infants. 

When working with a pregnant person, Munoz helps to create a balanced, diverse and nutrient-dense prenatal diet. In addition, Munoz will go through common allergens with the family and help them devise a dietary plan for the child, introducing and maintaining these common allergens in their diet. 

When working with families with young infants, Munoz will assess a child’s risk for developing allergies by analyzing family history and the presence of eczema and devising a dietary plan from there. While there is no default list of allergens to introduce first, egg and peanuts are typically the ones they recommend to start introducing in the diet first. 

In addition, for some patients with a strong family history of food allergies — for example, in a household where an older sibling has a food allergy — it can be difficult to introduce these allergens into the child’s diet. The program aims to design practical strategies to combat this, such as introducing the food in the allergist’s office or at a grandparent’s or other close relative’s house.

“While [the LEAP study] focused on peanuts, the data provided the framework for introducing and maintaining other top allergens in an infants’ diets,” Munoz wrote. “We are hopeful that in years to come there will be more research looking into tolerance development at this young age that can be weaved into our practice.”

Using the LEAP trial as a model, the potential end point for this program would be between ages 5 to 6; however, they may opt for longer depending on the patient.

Over 10 percent of the U.S. population has food allergies.