Is Community-Acquired Methicillin-Resistant Staphylococcus aureus Coverage Needed for Cellulitis?

Methicillin-resistant Staphylococcus aureus (MRSA) has become the dominant strain of Staphylococcus aureus in many communities of the United States. As a result, many clinicians are now empirically covering for this pathogen in the treatment of various skin and soft-tissue infections. Should this practice apply to cellulitis? In order to answer this question, we defined cellulitis and reviewed the pathogenesis, microbiology, and current studies of inpatient and outpatient antimicrobial therapy. The current evidence suggests empirical MRSA coverage for community-acquired cellulitis may not be necessary in non-purulent (non-suppurative) forms of this infection. Most cases are non-purulent and not amenable to culture although antibody studies indicate streptococci are the most common etiologic agents. Current studies of antimicrobial therapy tend to agree with this finding. Empirical beta-lactam therapy directed primarily at streptococci appears sufficient for non-purulent cellulitis regardless of the prevalence of MRSA in the community.