A major international study involving over 5,000 hospital patients has revealed that direct oral challenge (DOC) testing for penicillin allergy effectively removes incorrect allergy labels. This breakthrough significantly reduces the prescription of World Health Organisation (WHO)-restricted antibiotics in hospitalized individuals.
Approximately 10% of hospitalized patients report a penicillin allergy, yet most of these reports are inaccurate. This often forces clinicians to use broader-spectrum or less effective antibiotics, fueling antimicrobial resistance and leading to poorer patient outcomes. The study, conducted across 40 hospitals in eight countries, assessed adult inpatients with reported penicillin allergies.
Of the 1,573 patients who underwent DOC, 95.5% were safely "delabelled" as not being allergic. Serious adverse events were rare, occurring in only 0.4% of cases. Crucially, patients who underwent DOC were 13 times more likely to receive penicillin and significantly less likely to be prescribed WHO "Watch" or "Reserve" antibiotics.
While 77 clinicians adopted the digital assessment tool within six months, logistical and clinical barriers, including staffing and risk perception, prevented all eligible patients from undergoing DOC. Despite these challenges, the findings strongly suggest that penicillin allergy testing via DOC is safe and effective for routine care. Wider implementation could improve antibiotic stewardship, enhance patient outcomes, and combat antimicrobial resistance.