A 28-year-old man presents with acute suppurative inflammation of the skin manifesting as a localized abscess with fluctuance and surrounding erythema. Gram stain and culture are pending. What is the drug of choice for empirical treatment of community-acquired skin and soft tissue infection (SSTI) in this patient?

Explanation

## First-Line Treatment of Community-Acquired SSTI with Abscess **Key Point:** 1st-generation cephalosporins (cephalexin, cefazolin) are the preferred empirical choice for community-acquired skin and soft tissue infections, including localized abscesses, because they provide excellent coverage of *Staphylococcus aureus* (including methicillin-susceptible strains) and *Streptococcus pyogenes*. ### Rationale for Cephalosporin Selection **High-Yield:** First-generation cephalosporins are ideal for acute SSTI because they: - Cover both *S. aureus* and *Streptococcus* species (the most common community SSTI pathogens) - Are β-lactams with rapid bactericidal activity - Achieve excellent skin and soft tissue penetration - Are cost-effective and well-tolerated - Represent the standard empirical choice before culture results ### Drug Comparison for Community-Acquired SSTI | Drug | Spectrum | *S. aureus* Coverage | SSTI Efficacy | Status | |------|----------|---------------------|---------------|--------| | Cephalexin (1st gen) | Gram+/some gram− | MSSA excellent | Gold standard | First-line | | Penicillin V | Gram+ (limited) | Poor (MSSA only) | Inadequate | Outdated | | Vancomycin | Gram+ (broad) | MRSA excellent | Reserved | 2nd-line/MRSA | | Clindamycin | Gram+/anaerobes | Variable (resistance) | Alternative | Backup option | **Clinical Pearl:** Acute suppurative inflammation (abscess formation) requires rapid bactericidal therapy. The combination of good *S. aureus* coverage + rapid killing + excellent tissue penetration makes 1st-gen cephalosporins the empirical standard in community settings where MRSA prevalence is low. **Warning:** Do NOT use penicillin V monotherapy for SSTI — it has poor *S. aureus* coverage and is considered outdated for this indication. Vancomycin is reserved for confirmed or suspected MRSA or severe/hospitalized cases. **Mnemonic:** **CEPHALOSPORIN FOR COMMUNITY SSTI** — 1st-generation cephalosporins are first-line for empirical community-acquired skin infections; vancomycin is reserved for MRSA risk or hospital-acquired disease.