Do we really need to cover MRSA?
For uncomplicated cellulitis, cephalexin alone was just as good as combined TMP-SMX plus cephalexin in the per-protocol analysis. "Per-protocol" patients took most of the medication and followed up in person. There was also no statistical difference in the intention-to-treat analysis, though the upper confidence interval exceeded 10%. Be aware of the study's exclusion criteria. It only evaluated uncomplicated cellulitis, confirmed to have no abscess on bedside ultrasound. Therefore, patients with abscess/furuncle, IVDA, immunocompromise, (and more...) were excluded. The study concluded enrollment 5 years ago; organisms and resistance patterns may have changed or may be different in your hospital. The IDSA recommended monotherapy with cephalexin for non-purulent cellulitis years ago.
For uncomplicated cellulitis in otherwise healthy patients, cephalexin alone is probably adequate. Read more on EM Lit of Note.
Effect of Cephalexin Plus Trimethoprim-Sulfamethoxazole vs Cephalexin Alone on Clinical Cure of Uncomplicated Cellulitis: A Randomized Clinical Trial. JAMA. 2017 May 23;317(20):2088-2096. doi: 10.1001/jama.2017.5653.
Peer Reviewed by Thomas Davis.