Postoperative wound infection rates following diagnostic skin biopsies in dermatology patients at an Australian tertiary hospital

Risk Factors for Surgical Site Infection after Minor Dermatologic Surgery

BACKGROUND

Surgical site infection (SSI) after dermatologic surgery is associated with poor outcomes including increased recovery time, poor cosmesis, and repeat visits to doctors. Prophylactic antibiotics are prescribed to reduce these adverse outcomes. Identifying risk factors for SSI will facilitate judicious antibiotic prophylaxis.

OBJECTIVE

To identify risk factors for SSI after minor dermatologic surgery.

METHODS

Individual patient data from four large randomized controlled trials were combined to increase statistical power. A total of 3,819 adult patients requiring minor skin procedures at a single facility were recruited over a 10-year period. The main outcome measure was SSI.

MAIN RESULTS

A total of 298 infections occurred, resulting in an overall incidence of 7.8% (95% confidence interval [CI], 5.8-9.6), although the incidence varied across the four studies (P = .042). Significant risk factors identified were age (relative risk [RR], 1.01; 95% CI, 1.001-1.020; P = .008), excisions from the upper limbs (RR, 3.03; 95% CI, 1.76-5.22; P = .007) or lower limbs (RR, 3.99; 95% CI, 1.93-8.23; P = .009), and flap/two-layer procedures (RR, 3.23; 95% CI, 1.79-5.85; P = .008). Histology of the excised lesion was not a significant independent risk factor for infection.

CONCLUSIONS

This study demonstrated that patients who were older, underwent complex excisions, or had excisions on an extremity were at higher risk of developing an SSI. An awareness of such risk factors will guide evidence-based and targeted antibiotic prophylaxis.