More than one-third of infants with a suspected peanut allergy did not react during a supervised food challenge, an Australian study has found.

The research was led by the Murdoch Children's Research Institute (MCRI) and the National Allergy Centre of Excellence (NACE). Investigators assessed 1,275 infants under 18 months old across 10 paediatric public hospitals, with 778 undergoing supervised oral food challenges.

All the children had previously recorded a reaction and tested positive on initial screening. Yet when clinicians conducted supervised oral food challenges, 35% showed no allergic reaction whatsoever.

The findings have enabled doctors to lift incorrect allergy diagnoses safely. 'Being able to identify those children early allows them to avoid an unnecessary allergy label and the burden of avoiding peanut,' said Dr Tim Brettig, MCRI senior research clinician.

Supervised Hospital Challenges Help Confirm Peanut Allergy

During a supervised challenge, medical teams give infants gradually increasing doses of peanut to monitor biological responses safely.

Of the 778 infants who underwent the challenge, 65% had an allergic reaction. Among those who reacted, 12% experienced anaphylaxis, a potentially life-threatening allergic reaction. Hospital staff managed every adverse reaction without lasting injury.

The remaining 35% had no reaction and were considered peanut tolerant, allowing their allergy labels to be removed.

These tolerant infants were cleared to eat age-appropriate peanut products, such as smooth peanut butter, as part of their normal diet.

One mother, Leah, described her anxiety before her son Arthur underwent testing after developing facial hives at five months old.

'We were understandably anxious going into the challenge, because we didn't know how Arthur would respond,' she said. 'It's a huge relief knowing Arthur can tolerate peanut and we can move forward without the uncertainty of managing a suspected allergy'.

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Oral Immunotherapy Offers Targeted Long-Term Tolerance

The programme offers oral immunotherapy, a treatment involving daily doses of peanut to help build tolerance in children with confirmed allergies.

Of the 394 infants who proceeded to oral immunotherapy, 97.5% successfully started treatment at a dose guided by their challenge results.

The findings suggest that clinical history and allergy testing alone may not always be sufficient to confirm peanut allergy, making supervised oral food challenges an important part of diagnosis.

NACE director Professor Kirsten Perrett urged health services to make hospital feeding challenges standard practice.

'Our results show that clinical history and allergy testing alone were not enough to accurately diagnose peanut allergy in many cases,' Professor Perrett said.

Australia records some of the highest childhood allergy rates worldwide, with peanut allergies affecting roughly one in 30 children. In the United States, the condition impacts approximately one in 50 children.

Medical Guidance Warns Against At-Home Testing

Immunologists have strongly warned parents never to attempt giving peanuts to suspected allergic children at home without specialist medical support.

Because more than one in ten reacting infants experienced acute anaphylaxis during the trial, medical supervision remains critical.

'This is not something to try at home — 12% of those babies had anaphylaxis,' said immunologist Dr Tania Elliott. 'This needs to happen in a monitored setting in the doctor's office, where they're given small amounts of peanut to determine if they're still allergic'.

Dr Elliott added that paediatric specialists should retest allergic children annually to check whether they have outgrown the condition.

Current paediatric guidelines from the American College of Allergy, Asthma & Immunology recommend introducing age-appropriate peanut foods early, typically between four and six months of age.

Parents who suspect their baby has a food allergy should speak to a GP for a referral to a specialist paediatric clinic.

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