Childhood food allergies significantly reduced in US since early peanut exposure guidelines

Childhood food allergies in the United States have significantly declined in the past decade following the adoption of early peanut exposure guidelines, according to new research from the Children’s Hospital of Philadelphia (CHOP).

Published in Pediatrics, the study reports sharp declines in diagnoses of peanut and other IgE-mediated food allergies following the guidelines. These findings highlight how landmark clinical research has translated into a successful public health campaign.

“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 first author Dr Stanislaw Gabryszewski, attending physician in CHOP’s Division of Allergy and Immunology. “We now have data that suggest that the effect of this landmark public health intervention is occurring.”

The shift to early exposure

IgE-mediated food allergies affect about four percent of children, often triggering immediate and potentially life-threatening reactions such as hives, swelling, vomiting or breathing difficulties. Peanuts are one of the most common allergens.

The shift towards early exposure was driven by the 2015 Learning Early About Peanut Allergy (LEAP) trial. That landmark study showed that introducing peanut to infants aged four to 11 months with severe eczema or egg allergy reduced the risk of peanut allergy by 81 percent. Subsequent studies confirmed the protective effect lasted beyond early childhood.

In response, paediatric, allergy and immunology organisations developed guidelines in 2015 and 2017 encouraging early introduction of peanuts, initially for high-risk infants. Updated recommendations in 2021 expanded this approach and advised parents to introduce peanut, egg and other allergenic foods between four and six months for all children without prior allergic reactions.

Key findings

To assess the impact of these measures, CHOP researchers analysed electronic health records from the American Academy of Pediatrics Comparative Effectiveness Research through Collaborative Electronic Reporting (CER2) network, which covers multiple US states. The researchers compared rates of food allergy diagnosis across different time periods: before the establishment of early introduction guidelines, after the first set of guidelines, and following the later addendum guidelines.

They found that from the time before the guidelines to after the addendum guidelines were introduced, peanut allergy prevalence fell from 0.79 percent to 0.45 percent of the study population, a reduction of around 43 percent. Overall IgE-mediated food allergies dropped from 1.46 percent to 0.93 percent, a reduction of about 36 percent. Peanut also moved from being the most common to the second most common childhood food allergen, surpassed by egg.

The authors estimated that for every 200 infants exposed to food allergens early in life, one case of food allergy was prevented.

While early peanut exposure does not eliminate childhood food allergies entirely, the study underscores the success of a preventive approach. The researchers emphasise that further awareness and education will be key to building on these gains.

“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 author Dr David Hill, attending physician in CHOP’s Division of Allergy and Immunology.

“Future studies could potentially explore specific feeding practices that help us better understand the timing, frequency and dose of foods that optimise protection against food allergies.”