Research could reverse peanut allergy diagnosis for some infants

More than one third of babies thought to have a peanut allergy may actually be able to safely eat nuts, according to a new study.

Researchers say the study could change the way the healthcare system approaches infant food allergies and lead to many children having their allergy diagnosis removed.

The research was led by the Murdoch Children's Research Institute and the National Allergy Centre of Excellence (NACE) in partnership with 10 paediatric public hospitals across Australia.

Researchers found 35 per cent of infants with a previous reaction to peanut and a positive allergy test did not react to an oral food challenge.

NACE Director Kirsten Perrett said the number of children who did not react to peanut during a supervised food challenge was "surprising".

"These were children that had had a history of reactions when they were introduced to peanuts and they'd had a positive test, be it a skin prick test or a blood test," Professor Perrett told ABC News Breakfast.

"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."

Melbourne School of Public Health biostatistics professor Lyle Gurrin, who was not involved in the research, said he was not surprised that the figure reported in the research was so high.

"A lot of people think their children are allergic when they're probably not, so I think this paper is good from that point of view that it's encouraging people to seek proper advice," he said.

"I'm not surprised that a large proportion of these infants didn't return a positive result in an oral food challenge."

The study involved 1,275 infants under 18 months of age at hospitals in Victoria, New South Wales, Queensland, South Australia and Western Australia.

The findings emerged from the ADAPT Peanut Oral Immunotherapy Program hosted by the Murdoch Children's Research Institute, which required infants to undergo a food challenge before starting treatment.

The program exposed children to small, daily doses of peanut to build tolerance. 

Victorian couple Leah and Jake introduced their infant son Arthur to peanuts when he was five months old.

They said the reaction was instant, with his face turning red and hives appearing on his shoulders and under his nose.

The boy was referred to the ADAPT program but then tolerated the supervised oral 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," Leah said.

"Having the opportunity to find out he could tolerate peanuts has made a real difference to our family."

Professor Perrett said it was hoped the research would make the process of identifying food allergies more accurate for parents like Leah and Jake.

"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," she said.

"We want to reduce the burden of food allergy for children and their families, and the ADAPT Program is a step in this direction."

Professor Gurrin said the research did not necessarily mean it would become easier for GPs to better diagnose a child with a peanut allergy.

He said oral food challenges still need to be carried out under appropriate conditions.

"You can't really do that in a GP surgery or a child maternal health clinic," he said.

"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."

Professor Perrett said NACE was hoping to expand the ADAPT program to cover cashew allergy, which was almost as prevalent as peanut allergy.

However, Professor Perrett advised parents not to conduct an oral food challenge at home, warning that 12 per cent of infants with a peanut allergy had a potentially-life threatening anaphylactic response.