Misdiagnosis of Penicillin Allergy Presents Serious Risks for Knee Surgery Patients

A recent study conducted by the University of Hong Kong has highlighted a significant health risk stemming from incorrect penicillin allergy labels, especially among patients undergoing knee replacement surgeries. The research revealed that inaccurately diagnosed penicillin allergies are associated with a heightened risk of developing periprosthetic joint infections (PJI), which can lead to severe complications, prolonged hospital stays, and higher medical costs.

The study focused on over 4,700 knee procedures performed at Queen Mary Hospital between 1993 and 2021. Findings indicated that patients with falsely labeled penicillin allergies were three times more likely to experience postoperative infections. Furthermore, this mislabeling was identified as an independent risk factor, increasing the likelihood of infection nearly five-fold. Such infections often necessitate additional surgeries, long-term antibiotic treatments, and can even result in increased mortality.

In Hong Kong, approximately 2% of the population, equating to over 140,000 individuals, are recorded as allergic to penicillin or related beta-lactam antibiotics. Alarmingly, up to 90% of these allergy records are believed to be incorrect, often based on outdated or inaccurate medical documentation. Many of these labels stem from childhood reactions or previous skin tests conducted outside Hong Kong, which may not be reliable.

This widespread mislabeling leads healthcare providers to prescribe alternative antibiotics that are less effective and carry additional risks. Consequently, patients face higher infection risks and suboptimal treatment outcomes.

To address this issue, HKUMed has introduced a pharmacist-led pilot program that offers direct access for patients to undergo penicillin allergy assessments without prior specialist referral. Trained pharmacists evaluate patients' allergy histories and facilitate further testing if needed, with seamless referral to allergists for confirmatory diagnosis. This community-based approach aims to improve patient safety by accurately identifying true allergies, thereby enabling the appropriate use of first-line antibiotics.

The initiative underscores a broader commitment to patient safety and optimal surgical outcomes. Experts emphasize the importance of reviewing and verifying allergy labels through proper testing, which can significantly reduce the risk of infections and improve treatment efficacy.

Overall, correcting misinformation about penicillin allergies is vital in preventing serious postoperative infections and ensuring safer healthcare practices. This innovative approach not only benefits individual patients but also alleviates the pressure on hospital allergy clinics, setting a new standard for community-based allergy management in Hong Kong. Source: https://medicalxpress.com/news/2025-08-incorrect-penicillin-allergy-diagnosis-linked.html