Adding trimethoprim-sulfamethoxazole to cephalexin did not produce superior outcomes in the treatment of uncomplicated cellulitis compared with cephalexin alone.

Physicians ponder the proper treatment for cellulitis. Is the infecting organism Streptococcus or Staphylococcus, and if Staphylococcus, is it a methicillin-resistant S. aureus (MRSA) strain? Cultures are difficult to obtain, and about 70% fail to isolate an infecting organism from blood, needle aspiration, or skin biopsy. To assess the benefit of adding antibiotics targeting community-acquired MRSA to cellulitis therapy, these authors enrolled 146 patients in a randomized, multicenter, double-blind, placebo-controlled trial.

Patients had cellulitis of less than 1-week duration without abscess, diabetes, immunosuppression, peripheral vascular disease, or hospitalization. All received adequate dosage of cephalexin based on weight, and 73 also received weight-based doses of trimethoprim-sulfamethoxazole (TMP-sulfa). Follow-up examinations at day 12 (±2 days) and at 1 month showed clinical cure in 62 of 73 cephalexin/TMP-sulfa recipients (85%) and 60 of 73 cephalexin/placebo recipients (82%). Twenty-one patients failed treatment. Nasal colonization data showed MRSA colonization in 4.9% of patients (all community acquired); such colonization was not associated with response to therapy.

CITATION(S):

Pallin DJ et al. Comparative effectiveness of cephalexin plus trimethoprim-sulfamethoxazole vs. cephalexin alone for treatment of uncomplicated cellulitis: A randomized controlled trial. Clin Infect Dis 2013 Mar 1; [e-pub ahead of print].