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 40-60 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.

TRIAL REGISTRATION NUMBER: ANZCTR 365115; Post-results.