Should We Add Trimethoprim-Sulfamethoxazole to Cephalexin for Cellulitis Treatment?

Determining which bacteria are causing a case of uncomplicated cellulitis seldom is possible, so treatment usually is empirical, guided by the affected area's appearance. In the absence of pus, antibiotics are targeted against β-hemolytic streptococci, but many clinicians now wonder if they should cover community-acquired methicillin-resistant Staphylococcus aureus (MRSA) as well.

In this multicenter, double-blind, placebo-controlled trial, researchers randomized 500 outpatients with acute cellulitis (and no abscess or purulent drainage) to receive a 7-day course of either oral cephalexin alone or cephalexin with trimethoprim-sulfamethoxazole (TMP-SMX) added for MRSA coverage. No patients were immunocompromised, only 11% were diabetic, and o…