One in three babies thought to have peanut allergy may actually not have the condition, landmark study shows

A third of babies thought to have peanut allergies may actually not have the condition, according to a landmark Australian study of over a thousand infants that could transform healthcare for allergies in children.

Peanut allergy is the most common form of food allergy, known to affect up to three per cent of children in Western nations.

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

The condition is caused by an overreaction of the body’s immune system to proteins found in peanuts.

Symptoms can kick in within minutes to two hours of exposure and can range from mild hives, itching, or swelling of the lips and tongue, to more life-threatening ones like wheezing, shortness of breath, or a tight throat.

In some cases, it may even lead to anaphylaxis, a medical emergency caused by a rapid pulse or loss of consciousness that can be fatal if not treated immediately.

Now, a world-first national programme in Australia has discovered that more than a third of babies thought to have a peanut allergy could safely have the diagnosis removed.

Researchers, including those from the National Allergy Centre of Excellence (NACE) in partnership with 10 paediatric public hospitals across Australia, found that 35 per cent of infants with a recent reaction to peanuts and a positive allergy test didn’t react during an oral food challenge.

Overall, the study assessed 1275 infants under 18 months old.

Over 750 children in the study underwent an oral food challenge, in which they received increasing doses of peanut under medical supervision to check for an allergic reaction.

“Oral food challenge should be routinely considered in infant peanut allergy evaluation,” scientists wrote in the Journal of Allergy and Clinical Immunology: In Practice.

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, researchers said.

The remaining 35 per cent of children in the study who had no reaction were considered peanut tolerant and could have their allergy label removed, the study noted.

If not for the food challenge, these children would likely have continued avoiding peanuts, fearing they could trigger an allergic reaction.

The findings highlight the importance of confirming a peanut allergy with a carefully monitored food challenge 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,” said Tim Brettig, senior author of the study from the Murdoch Children’s Research Institute in Victoria.

“Being able to identify those children early allows them to avoid an unnecessary allergy label and the burden of avoiding peanut,” Dr Brettig said.

Those who developed an allergic reaction in the study were given peanut oral immunotherapy, a treatment involving daily doses of peanut to build tolerance.

About 97 per cent of them successfully started treatment at a dose guided by their challenge results.

“Oral food challenges are not currently used routinely for every infant with suspected peanut allergy. But our results show that clinical history and allergy testing alone were not enough to accurately diagnose peanut allergy in many cases,” NACE director Kirsten Perrett said.

“A supervised oral food challenge should be routinely considered to confirm the diagnosis before an infant starts oral immunotherapy,” Dr Perrett said.