LAUSR

BACKGROUND Benzoyl peroxide (BPO) solutions effectively reduce Cutibacterium acnes (formerly Propionibacterium acnes) on the face, neck, and back in nonoperative settings. This study compared preoperative application of BPO vs. chlorhexidine gluconate (CHG) in decreasing shoulder C acnes skin burden in surgical patients. METHODS Eighty patients undergoing shoulder surgery were prospectively enrolled in a randomized double-blind trial at 1 institution from August 2015 to April 2017. Participants were randomized to 5% BPO or 4% CHG for 3 consecutive days. The nonoperative shoulder had no intervention and served as the negative control. Skin cultures of both shoulders were obtained via a detergent scrub technique the day of surgery at anterior, lateral, and posterior sites and the axilla. RESULTS Fewer positive cultures were obtained from the BPO-treated side compared with the contralateral side (P = .0003), and no change was shown for the CHG group (P = .80). Shoulders treated with BPO showed a statistically significant reduction in C acnes counts compared with CHG at anterior (P = .03) and posterior (P = .005) portal sites. No significant difference was found at the axilla (P = .99) or lateral portal site (P = .08). No postoperative infections or wound complications occurred in either group. CONCLUSIONS BPO is more effective than CHG at reducing C acnes on the shoulder. Decreasing the skin burden of C acnes may reduce intraoperative wound contamination and postoperative infection. BPO should be considered as an adjunctive preoperative skin preparation considering its potential benefit, low risk, and low cost.