• Posted October 22, 2025

Early Exposure Guidelines Cut Down Peanut Allergy Cases

Encouraging parents to introduce peanuts to their infants early has led to a significant drop in new allergy diagnoses, according to researchers at the Children’s Hospital of Philadelphia.

Their study —  published in the November issue of the journal Pediatrics — is the first large-scale analysis to show the real-world impact of the new feeding recommendations and a successful public health intervention.

Anaphylactic food allergies — in which the immune system overreacts to foods like milk, egg or peanut — affect about 4% of children and can cause immediate, severe reactions such as hives, swelling and difficulty breathing. 

Peanut is among the most common causes of these reactions, which are also known as immunoglobulin E (IgE)-mediated.

The shift in public health policy was driven by the 2015 Learning Early About Peanut Allergy (LEAP) trial, which found that regularly feeding peanut products to high-risk infants (those with severe eczema or egg allergy) reduced their risk of developing a peanut allergy by 81%.

Following the LEAP trial, major pediatric and allergy organizations released guidelines in 2015 and 2017 focused on high-risk children. 

These were broadened in 2021 to support having caregivers introduce major food allergens like peanut and egg at 4 to 6 months of age for all children without a history of a prior reaction.

“Everyone has been wondering whether these landmark public health interventions have had an impact on reducing rates of IgE-mediated food allergies in the United States,” said Dr. Stanislaw Gabryszewski, the study’s first author and an attending physician at Children’s Hospital of Philadelphia (CHOP). “We now have data that suggest that the effect of this landmark public health intervention is occurring.”

Analyzing the Decline

The CHOP team analyzed electronic health record data for more than 124,000 children. They compared food allergy diagnosis rates before the guidelines; after the initial guidelines; and after broader 2021 guidelines were adopted.

From before the 2015 guidelines to after the 2021 addendum, the results showed a significant reduction in new diagnoses of:

• Peanut Allergy: Down from 0.79% to 0.45% of children in the study

• Any IgE-Mediated Food Allergy: Down from 1.46% to 0.93% of children in the study

For roughly every 200 infants who received early exposure to food allergens, the authors estimated that one child was prevented from developing a food allergy. 

Furthermore, egg allergy surpassed peanut allergy as the most commonly diagnosed food allergy after the guidelines were put in place.

While the early exposure approach doesn't completely eliminate food allergies, experts consider the observed reduction a major public health victory.

“Our findings have relevance from those of us who treat patients to those caring for infants, and more awareness, education and advocacy could further increase the positive results we observed in this study,” said senior study author Dr. David Hill, an attending physician with the Division of Allergy and Immunology at CHOP.

Dr. Hill noted that “future studies could potentially explore specific feeding practices that help us better understand the timing, frequency and dose of foods that optimize protection against food allergies.”

In an accompanying editorial, writers welcomed the findings and called for continued follow up on them.

"If confirmed, these findings would represent a meaningful public health advance — affirming that clinical research, when coupled with clear guidelines and committed dissemination, can indeed shift the trajectory of childhood food allergy," wrote a team led by Dr. Ruchi Gupta of Northwestern University Feinberg School of Medicine in Chicago.

More information

The National Institute of Allergy and Infectious Diseases offers resources on food allergies.

SOURCES: Children’s Hospital of Philadelphia, news release, Oct. 20, 2025; Pediatrics, November 2025