Australian study finds over a third of infants suspected of peanut allergy test negative in food challenges

A national programme across ten paediatric public hospitals in Australia evaluated 1,275 infants under 18 months who had a recent reaction to peanut and positive allergy tests. Of the 778 children who underwent supervised oral food challenges, 35% did not react, indicating they were peanut tolerant and could safely reintroduce the food.

"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," said Dr Tim Brettig, senior research clinician with the Murdoch Children’s Research Institute’s Population Allergy Group.

The challenges also identified infants who reacted; 65% experienced an allergic response, including 12% who developed anaphylaxis, all of which were managed by clinical teams. Those who reacted were offered peanut oral immunotherapy, with 97.5% beginning treatment based on challenge results.

Professor Kirsten Perrett, director of the National Allergy Centre of Excellence and lead of the ADAPT program, emphasized that clinical history and testing alone were insufficient for accurate diagnosis. "Oral food challenges are not currently used routinely for every infant with suspected peanut allergy, but our results show that a supervised oral food challenge should be routinely considered to confirm the diagnosis before an infant starts oral immunotherapy," she said.

The researchers recommend that families suspecting a peanut allergy consult their GP, who may refer them to a paediatric allergy specialist for assessment.