Study finds many Australian infants misdiagnosed with peanut allergy

A collaborative study by the Murdoch Children’s Research Institute, the National Allergy Centre of Excellence and ten paediatric hospitals across Australia found that roughly one in three infants with suspected peanut allergy were able to tolerate the legume during a medically supervised oral food challenge. Of the 778 infants enrolled in the ADAPT oral immunotherapy program, 271 passed the challenge and were advised to re-introduce peanuts into their regular diet, eliminating the need for further immunotherapy.

"It’s paradigm-shifting in terms of how we diagnose infant peanut allergy," said Professor Kirsten Perrett, leader of the MCRI population allergy group and director of NACE. She added that a history of reaction combined with a positive skin-prick or blood test was insufficient to confirm allergy in many cases.

The oral food challenge, considered the gold-standard diagnostic tool, involved giving increasing amounts of peanut powder under strict medical supervision. While about 65% of participants reacted during the challenge, 12% experienced anaphylaxis, underscoring the need for specialist oversight when re-introducing allergens.

Parents of participants highlighted practical barriers to accessing the test. Leah, whose son Arthur was diagnosed with a peanut allergy after a reaction at five months, said the challenge was “reassuring” after he successfully consumed two tablespoons of peanut powder without symptoms. She called for improved availability of oral food challenges, especially in regional areas, noting the travel and accommodation costs involved.

The researchers suggest that some infants may have a transient allergy that resolves within months, or that an initial reaction does not necessarily predict ongoing sensitivity. The findings could influence future diagnostic protocols for infants, though implications for older children and adults remain uncertain.