One in three babies diagnosed with a peanut allergy may not actually have the condition, according to a landmark Australian study that could transform how infant food allergies are managed.
The research, led by the Murdoch Children’s Research Institute (MCRI) and the National Allergy Centre of Excellence (NACE), found that 35 per cent of infants with a previous reaction to peanut and a positive allergy test did not react during a medically supervised oral food challenge.
Study Findings and Methodology
The study, published in The Journal of Allergy and Clinical Immunology: In Practice, assessed 1,275 infants under 18 months of age across 10 paediatric public hospitals in Australia between April 2024 and October 2025. Of these, 778 infants underwent an oral food challenge, where they received increasing doses of peanut protein under medical supervision.
During the challenges, 65 per cent of the babies had a reaction, including 12 per cent who experienced anaphylaxis, a potentially life-threatening allergic response. However, all reactions were safely managed by the medical teams. The remaining 35 per cent of children showed no reaction, allowing their peanut allergy diagnosis to be removed.
“This rate is much higher than we thought,” said Dr. Timothy Brettig, a pediatric allergist at the National Allergy Centre of Excellence and a co-author of the study.
The researchers said that while skin-prick and blood tests can indicate a sensitivity to peanuts, they do not always confirm a true allergy that causes a reaction upon ingestion.
Impact on Diagnosis and Treatment
The findings challenge the decades-long approach of diagnosing peanut allergy based solely on a history of reaction and positive allergy tests.
“Oral food challenges are not currently used routinely for every infant with suspected peanut allergy,” said Professor Kirsten Perrett, Director of NACE and lead of the ADAPT program. “But our results show that clinical history and allergy testing alone were not enough to accurately diagnose peanut allergy in many cases.”
Professor Perrett emphasized that a supervised oral food challenge should be routinely considered to confirm a diagnosis before an infant starts oral immunotherapy, a treatment involving daily doses of peanut to build tolerance.
The study also highlighted the success of the oral immunotherapy program for those who did react. Of the infants who reacted during the challenge and began treatment, 97.5 per cent successfully started the therapy, with doses guided by their individual reaction thresholds.
Arthur's Peanut Allergy Diagnosis Was Removed Through Supervised Testing
The study included the case of Arthur, a baby who was diagnosed with a peanut allergy at five months old after a reaction. His family was referred to the ADAPT program, where he passed a supervised food challenge and had his allergy diagnosis removed.
“It's a huge relief knowing Arthur can tolerate peanut and we can move forward without the uncertainty of managing a suspected allergy,” Arthur’s mother, Leah, said. “Having the opportunity to find out he could tolerate peanuts has made a real difference to our family.”
Despite the positive outcomes, researchers strongly advised against parents conducting food challenges at home. Dr. Brettig said that 12 per cent of infants in the study experienced anaphylaxis, which requires immediate medical intervention.
“You can't really do that in a GP surgery or a child maternal health clinic,” said Lyle Gurrin, a professor not involved in the research. “You need all the material and the broader understanding to be able to assist the child who is having a reaction, whether it be mild or right through to anaphylaxis.”
The researchers hope their findings will lead to a paradigm shift in diagnosing infant peanut allergies, reducing unnecessary dietary restrictions and anxiety for families while ensuring children with genuine allergies receive proper care.
Earlier coverage: New Study: Over One-Third of Babies May Outgrow Peanut Allergies
