Clinical Characteristics of Lower Extremity Surgical Site Infections in Dermatologic Surgery Based Upon 24-Month Retrospective Review

July 2018 | Volume 17 | Issue 7 | Original Article | 766 | Copyright © July 2018

Omar Bari BA,a Robert E. Eilers Jr. MD,b Ashley G. Rubin MD,c Shang I Brian Jiang MDa

aUniversity of California San Diego, La Jolla, CA bRiverchase Dermatology, Naples, FL cCarlsbad and Vista Dermatology, Vista, CA

Dermatologic surgery performed on the lower extremities has an increased risk for surgical site infections (SSI). Our objective was to evaluate the clinical characteristics associated with SSI following Mohs micrographic surgery (MMS) and wide local excisions (WLE) performed below the knee. We performed a single-center retrospective chart review of patients (n=271) that underwent these procedures. Within 14 days of the lower extremity procedure, four of 175 MMS patients (2.3%) developed SSI compared to eight of 96 WLE patients (8.3%; P=0.029). Subcuticular sutures and vertical mattress sutures as a group were associated with reduced 30-day infection rate when compared to other suture methods (P=0.006). Comparison of patients on prophylactic antibiotics to control patients without antibiotics did not reveal a statistically significant difference in infection rate. MMS infection rates trended lower as compared to WLE in the 14-day post-operative window. Doxycycline prophylaxis did not produce a statistically significantly lower rate of SSI, though results approached significance. A prospective study may be warranted to further compare cephalexin and doxycycline for dermatologic surgery below the knee. Subcuticular or vertical mattress sutures may be preferred when closing wounds due to their association with reduced infection rate. J Drugs Dermatol. 2018;17(7):766-771.


Dermatologic surgery, including Mohs micrographic surgery (MMS) and wide local excision (WLE), is associated with low rates of intraoperative and postoperative adverse effects. Futoryan and Grande found a combined infection rate of 2.3% when analyzing over 1,000 cases of both MMS and cutaneous excisions in 1995.1 A 2013 multicenter, prospective cohort study evaluating over 20,000 MMS procedures reported an adverse event incidence rate of 0.72%, with surgical site infections (SSI) being the most common adverse event reported.2There is an increased risk of SSI following dermatologic surgery on the lower extremities; an analysis of over 5,000 dermatologic surgery cases found a below the knee infection rate of 6.9%.3 Because of the increased SSI rate in the lower extremities, dermatologic surgeons routinely recommended the use of prophylactic antibiotics in patients undergoing dermatologic surgery below the knee.3 An advisory statement in 2008 reinforced this notion, urging surgeons to adopt prophylactic cephalexin.4 A 2012 review of antibiotic prophylaxis in dermatologic surgery echoed this appeal for prophylactic cephalexin in below the knee procedures.5To our knowledge, there are no studies investigating whether prophylaxis with doxycycline is superior to prophylaxis with cephalexin in the prevention of SSI on the lower extremities following dermatologic surgery. The choice of which prophylactic antibiotic to use, if any, is still largely left to the surgeon and is often determined on a case by case basis.5-7The objective of this study was to identify the clinical characteristics associated with SSI following dermatologic surgery below the knee. The type of procedure was examined to gauge if MMS or WLE were associated with differing infection rates. Additionally, the type of suturing method used was reviewed given the theoretic potential that running suture techniques may decrease perfusion to the skin. It is the surgeon’s choice which cutaneous suturing method to use, and the considerations include: tension, anatomical location, need for eversion and/or hemostasis, cosmesis, and time required to suture. Other clinical characteristics included patient comorbidities, as higher infection rates have previously been found in diabetic patients, immunosuppressed patients, smokers, and patients on anticoagulant medications.8-10


This study was approved by the Institutional Review Board of the University of California, San Diego (UCSD). Using the Epic electronic medical record system, the authors reviewed the