More than one-third of infants diagnosed with a peanut allergy may not be later found to have the condition, according to a study that highlights the importance of confirming suspected allergies before beginning long-term treatment.
Researchers from the Murdoch Children's Research Institute (MCRI) and the National Allergy Centre of Excellence (NACE) in Australia assessed 1,275 infants under 18 months through a national programme involving 10 paediatric hospitals.
Of these, 778 underwent supervised oral food challenges, in which infants were given gradually increasing doses of peanut under medical supervision to determine whether they experienced an allergic reaction.
The findings, published in the Journal of Allergy and Clinical Immunology: In Practice, showed that 65 per cent of the infants who underwent the challenges experienced an allergic reaction. The remaining 35 per cent showed no reaction and had their peanut allergy diagnosis removed.
All reactions during the study were safely managed by the medical teams.
The researchers said the findings demonstrated the value of confirming an infant's allergy status rather than relying solely on an initial diagnosis or positive allergy test.
Dr Tim Brettig, senior research clinician at MCRI's Population Allergy Group and medical lead of the ADAPT programme, said identifying infants who could tolerate peanut early would help avoid unnecessary dietary restrictions.
“Being able to identify those children early allows them to avoid an unnecessary allergy label and the burden of avoiding peanut,” he said.
The programme also highlighted the experience of Arthur, who was diagnosed with a peanut allergy at five months old. Following a referral to one of the participating hospitals, he underwent a supervised oral food challenge without reacting, and his diagnosis was subsequently removed.
His mother, Leah, said the family had been anxious before the test but was relieved that he could tolerate peanut.
Why are supervised food challenges important?
A positive allergy test does not always establish that a child will experience an allergic reaction when exposed to the food. A supervised oral food challenge can help clinicians establish whether an allergy is present by observing the child's response to gradually increasing amounts of the suspected allergen.
Peanut allergy is an immune system response to proteins in peanuts. Reactions can range from mild symptoms, such as itching, hives and swelling, to severe reactions involving breathing difficulties and anaphylaxis, which requires urgent medical attention.
An allergy diagnosis can also have a considerable impact on families, requiring them to monitor food ingredients, avoid potential exposure and remain prepared for accidental reactions.
The Australian researchers said oral food challenges should be routinely considered when evaluating infants with suspected peanut allergy.
Professor Kirsten Perrett, leader of MCRI's Population Allergy Group, director at NACE and lead of the ADAPT programme, said: “A supervised oral food challenge should be routinely considered to confirm the diagnosis before an infant starts oral immunotherapy.”
The recommendation is particularly relevant before starting treatments that involve regular exposure to the allergen.
What happens when an infant has a confirmed peanut allergy?
Almost all infants who experienced an allergic reaction during the study began a course of oral immunotherapy through the ADAPT Peanut Oral Immunotherapy Programme.
The treatment involves giving patients daily doses of peanut under a structured medical programme to help build tolerance over time. It is not a cure and must be undertaken with specialist supervision.
Professor Perrett said the programme aimed to reduce the burden of food allergies on children and their families.
The findings also come amid growing interest in early peanut introduction as a way of reducing the risk of developing an allergy.
The American College of Allergy, Asthma and Immunology advises that developmentally appropriate peanut-containing foods can be introduced to infants at around four to six months, rather than routinely delaying exposure. However, the timing and approach should take account of the child's individual allergy risk and medical history.
The Australian study does not suggest that parents should introduce peanut at home to infants with a suspected or diagnosed allergy. Its findings instead underline the importance of specialist assessment and supervised testing when confirming an allergy.
For healthcare professionals, the research highlights the need to distinguish between a positive allergy test and a clinically confirmed food allergy, helping families avoid unnecessary restrictions while ensuring children with genuine allergies receive appropriate care.
