Effect of a single prophylactic preoperative oral antibiotic dose on surgical site infection following complex dermatological procedures on the nose and ear: a prospective, randomised, controlled, double-blinded trial

Objectives There is limited published research studying the effect of antibiotic prophylaxis on surgical site infection (SSI) in dermatological surgery, and there is no consensus for its use in higher-risk cases. The objective of this study was to determine the effectiveness of a single oral preoperative 2 g dose of cephalexin in preventing SSI following flap and graft dermatological closures on the nose and ear. Design Prospective double-blinded, randomised, placebo-controlled trial testing for difference in infection rates. Setting Primary care skin cancer clinics in North Queensland, Australia, were randomised to 2 g oral cephalexin or placebo 40-60 min prior to skin incision. Participants 154 consecutive eligible patients booked for flap or graft closure following skin cancer excision on the ear and nose. Intervention 2 g dose of cephalexin administered 4060 min prior to surgery. Results Overall 8/69 (11.6%) controls and 1/73 (1.4%) in the intervention group developed SSI (p=0.015; absolute SSI reduction 10.2%; number needed to treat (NNT) for benefit 9.8, 95% CI 5.5 to 45.5). In males, 7/44 controls and 0/33 in the intervention group developed SSI (p=0.018; absolute SSI reduction 15.9%; NNT for benefit 6.3, 95% CI 3.8 to 19.2). SSI was much lower in female controls (1/25) and antibiotic prophylaxis did not further reduce this (p=1.0). There was no difference between the study groups in adverse symptoms attributable to high-dose antibiotic administration (p=0.871). Conclusion A single oral 2 g dose of cephalexin given before complex skin closure on the nose and ear reduced SSI.