Supervised food challenges clear many infants of suspected peanut allergy

A world-first national program has discovered more than a third of babies thought to have a peanut allergy could safely have the diagnosis removed. And the findings are changing how Australia's healthcare system approaches infant food allergies.

The research, led by Murdoch Children's Research Institute (MCRI) and the National Allergy Centre of Excellence (NACE) in partnership with 10 pediatric public hospitals across Australia, found 35 per cent of infants with a recent reaction to peanut and positive allergy test didn't react during an oral food challenge. Without the challenge, these children would have likely continued to avoid peanut in case they triggered an allergic reaction.

MCRI Population Allergy Group Senior Research Clinician and ADAPT Medical Lead Dr Tim Brettig said the study highlighted the importance of confirming a peanut allergy before committing children to long-term treatment.

We found more than one third of infants who were suspected to have peanut allergy based on their history and initial tests no longer reacted when they underwent a supervised food challenge. Being able to identify those children early allows them to avoid an unnecessary allergy label and the burden of avoiding peanut."

Dr Tim Brettig, MCRI Population Allergy Group Senior Research Clinician and ADAPT Medical Lead

The findings form part of a study evaluating the ADAPT Peanut Oral Immunotherapy Program, which was launched in 2024 by the NACE, hosted at MCRI. ADAPT is the first peanut allergy treatment program offered in Australian public hospitals for infants outside of a clinical trial setting.

As part of this evaluation, 1275 infants under 18 months old were assessed with 778 undergoing an oral food challenge. The infants presented at participating hospitals across Victoria, New South Wales, Queensland, South Australia and Western Australia. During a food challenge, infants receive increasing doses of peanut under medical supervision to check for an allergic reaction.

Published in The Journal of Allergy and Clinical Immunology: In Practice, it found while 65 per cent of babies had a reaction, including 12 per cent who experienced anaphylaxis, all episodes were safely managed by the teams conducting the food challenges.

The 35 per cent who had no reaction were considered peanut tolerant and could have their allergy label removed, allowing them to regularly eat peanut in an age-appropriate form, such as peanut butter.

Almost all babies who reacted proceeded to peanut oral immunotherapy, a treatment involving daily doses of peanut to build tolerance, with 97.5 per cent successfully starting treatment at a dose guided by their challenge results.

Australia has some of the highest reported rates of childhood food allergies in the world with peanut allergy affecting about one in 30 children.

MCRI Population Allergy Group Leader and NACE Director Professor Kirsten Perrett, also the ADAPT Program Lead, said the results had implications for how peanut allergy was managed in Australia.

"Oral food challenges are not currently used routinely for every infant with suspected peanut allergy," she said. "But our results show that clinical history and allergy testing alone were not enough to accurately diagnose peanut allergy in many cases. A supervised oral food challenge should be routinely considered to confirm the diagnosis before an infant starts oral immunotherapy.

"With peanut allergy one of the most common childhood food allergies, it's particularly important that we have an accurate diagnosis when a baby first shows signs of a possible peanut allergy. We want to reduce the burden of food allergy for children and their families, and the ADAPT Program is a step in this direction."

When Leah and Jake introduced their infant son to peanuts the reaction was almost immediate.

Just five months at the time, Arthur's face reddened and hives appeared on his shoulders and under his nose. The reaction settled within an hour, but the family was left unsure as to whether Arthur had a peanut allergy.

"Our GP referred us to an allergy specialist who took skin prick and blood tests," Leah said. "The results suggested Arthur had a high risk of reacting to peanut, and we were advised to avoid it while we awaited further tests."

Arthur, now one years old, was referred to the ADAPT Program at The Royal Children's Hospital (RCH). Despite his earlier side effects and allergy test results, Arthur tolerated the supervised oral food challenge without reacting. His suspected peanut allergy label was removed.

"We were understandably anxious going into the challenge, because we didn't know how Arthur would respond," Leah said.

"It's a huge relief knowing Arthur can tolerate peanut and we can move forward without the uncertainty of managing a suspected allergy. Having the opportunity to find out he could tolerate peanuts has made a real difference to our family."

Needing to travel to Melbourne for the food challenge, Leah hopes more families, particularly those in regional and remote areas, will have similar opportunities to clarify their child's diagnosis.

The NACE and National Allergy Council (NAC) were funded by the Federal Government in 2022 to transform allergy research and clinical care to help save lives, improve health and reduce the burden of allergic disease.

If families suspect their baby has a peanut allergy, they are encouraged to talk to their GP, who might refer them to a pediatric allergy specialist.