Austin Health has led the world’s largest study confirming that most patients labelled allergic to penicillin are not truly allergic, unlocking access to more effective antibiotics and transforming hospital care worldwide. 

Published today in Clinical Infectious Diseases journal, the international study involved more than 5,000 patients across 40 hospitals in Australia, the United Kingdom, the United States, Canada, Malaysia, South Africa, Hong Kong and New Zealand.  

The study led by Austin Health, in collaboration with the University of Melbourne, the Doherty Institute and the National Allergy Centre of Excellence (NACE), demonstrates for the first time that penicillin allergy testing can be safely delivered at scale as part of routine hospital care worldwide, building on earlier Austin Health research that was limited to smaller patient groups and specialist clinics. 

Around one in ten hospital patients are recorded as being allergic to penicillin, yet most are not truly allergic. Of the 1,573 patients who received a supervised test dose of penicillin as part of the study, 95 per cent were safely confirmed not to be allergic and had their medical records corrected, enabling clinicians to prescribe more effective first-line antibiotics and reduce delays in treatment. 

Austin Health Infectious Diseases Physician and Chief Principal Investigator Professor Jason Trubiano said incorrect penicillin allergy labels were a significant global healthcare challenge and the new study marked a critical shift from specialist research into global clinical practice. 

“Around 10 per cent of hospitalised patients globally report a penicillin allergy, however most are not truly allergic, often because they were misdiagnosed in childhood, outgrew it or it’s been years since their last reaction,” Professor Trubiano, also co-chair of the NACE drug allergy stream, said. 

“Misdiagnosis can result in inappropriate antibiotic prescribing, longer hospital stays, increased healthcare costs and more readmissions. 

“Our previous studies showed penicillin allergy testing could be done safely in smaller patient groups and specialist settings. This global study is a game-changer. For the first time, we have shown this approach can be safely implemented at scale across entire hospital systems, using technology to support clinicians and allowing hospitals worldwide to deliver this testing as part of routine care. For patients, that means faster access to the most effective antibiotics and better treatment outcomes.” 

A key innovation was the use of a purpose-built smartphone assessment tool, enabling doctors, pharmacists and nurses to identify low-risk patients and safely administer a supervised test dose of penicillin during routine hospital care, including in hospitals without specialist allergy services. 

Elise Mitri, Austin Health Drug Allergy Pharmacist and Project Coordinator, said the findings demonstrated the model could now be safely implemented at scale. 

“This study shows penicillin allergy testing can be safely integrated into everyday hospital care, ensuring patients receive the most appropriate and effective treatment,” Ms Mitri, NACE drug allergy PhD Scholar, said. “The model is already being rolled out in hospitals across Australia and internationally.” 

For Nathan, 35, participation in the study at Austin Health provided clarity after a lifetime of avoiding penicillin. 

“I have a medical condition that often requires immunosuppressant treatment that makes me more susceptible to respiratory infections,” Nathan said. 

“Now that I can have penicillin for flare-ups, I feel more at ease knowing I have access to a potentially lifesaving path of treatment if I need it.” 

Following the adult study, the model will be expanded to children at six hospitals across Australia in partnership with the National Allergy Centre of Excellence (NACE), hosted at the Murdoch Children’s Research Institute (MCRI). 

Professor Kirsten Perrett, Director of the NACE and MCRI Population Allergy Group Leader, said about 5 per cent of hospitalised children report a penicillin allergy and the rate only increased with age. 

“The new study will help assess hundreds of children with a reported penicillin, cephalosporin or sulfonamide allergy,” she said. “We will use an established assessment tool to identify children with a low-risk antibiotic allergy and offer a test dose. If their result is negative, they will have their antibiotic allergy label corrected, improving infection management and outcomes for children.” 

Professor Trubiano said the study demonstrated Austin Health’s leadership in improving patient care worldwide. 

“This research ensures patients receive the right treatment at the right time,” he said. “It highlights how work led at Austin Health, with support from Melbourne researchers, is improving care locally, nationally and internationally.”