Clinical question: Is empiric MRSA coverage for nonpurulent cellulitis necessary?
Background: Most nonpurulent skin and soft tissue infections are caused by beta-hemolytic streptococci and methicillin-susceptible Staphylococcus aureus. However, there is a growing incidence of community-acquired methicillin-resistant S. aureus infections. The authors of this study attempted to answer whether adding empiric methicillin-resistant S. aureus coverage reduces the risk of treatment failure.
Dr. Emily Ramee
Study design: Multicenter, double-blind, randomized superiority trial.
Setting: Five emergency departments in the United States.
Synopsis: The authors of this study randomized 500 patients with cellulitis without purulent drainage or evidence of abscess as confirmed by sonography to receive a 7-day course of either cephalexin with placebo or cephalexin plus trimethoprimsulfamethoxazole. When analyzing those patients who took most of the prescribed pills (greater than 75% of doses) according to treatment protocol, there was no significant difference in clinical cure rate between the two arms of the study, reaffirming current guidelines that advocate against empiric methicillin-resistant S. aureus coverage for uncomplicated cellulitis.
When the authors analyzed the result of their data with the assumption that patients who were lost to follow-up had treatment failure, there was a trend favoring the addition of trimethoprim-sulfamethoxazole with cephalexin over monotherapy with cephalexin (P = .07). Although the authors concluded that this finding may warrant further investigation, this was essentially a negative study.
Bottom line: Empirically adding community-acquired methicillin-resistant S. aureus coverage with trimethoprim-sulfamethoxazole to uncomplicated cellulitis did not statistically improve a clinical cure, compared with empiric treatment with monotherapy with cephalexin.
Citation: Moran GJ, Krishnadasan A, Mower WR, et al. Effect of cephalexin plus trimethoprim-sulfamethoxazole vs. cephalexin alone on clinical cure of uncomplicated cellulitis. JAMA. 2017;317(20):2088-96.
Dr. Ramee is a hospitalist at Ochsner Health System, New Orleans.