What antibiotics are recommended for a patient with a purulent skin wound and a history of Methicillin-Resistant Staphylococcus Aureus (MRSA)?

Treatment of Purulent Skin Wound with History of MRSA

For a purulent skin wound in a patient with a history of MRSA, incision and drainage is the primary treatment, followed by empiric antibiotic therapy with oral trimethoprim-sulfamethoxazole, clindamycin, doxycycline/minocycline, or linezolid. 1, 2

Initial Management

• Surgical debridement and drainage of associated soft-tissue abscesses is the mainstay of therapy and should be performed whenever feasible for MRSA wound infections 1
• Obtaining cultures from purulent drainage before starting antibiotics is crucial to confirm MRSA and guide definitive therapy 1
• For simple abscesses or boils, incision and drainage alone may be adequate without antibiotics, but additional antibiotics are recommended for more extensive infections 3

Antibiotic Selection

First-line oral options:

• Trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 DS tablets PO BID (4 mg/kg/dose of TMP component twice daily) is recommended as first-line therapy 1, 2
• Clindamycin 300-450 mg PO TID is effective if local resistance rates are low (<10%) and provides coverage for both MRSA and beta-hemolytic streptococci 1, 2
• Doxycycline 100 mg PO BID or minocycline 100 mg PO BID are effective alternatives 3, 2
• Linezolid 600 mg PO BID is highly effective but more expensive compared with other options 2, 4

When to use intravenous therapy:

• For patients with systemic toxicity, extensive disease, or rapidly progressive infections, inpatient management with IV antibiotics is recommended 2
• Vancomycin 15-20 mg/kg/dose IV every 8-12 hours is the first-line IV option for hospitalized patients 2
• Daptomycin 4-6 mg/kg IV once daily is an effective alternative for complicated skin infections 1, 5
• Linezolid 600 mg IV twice daily has shown excellent efficacy against MRSA skin and soft tissue infections with a clinical success rate of 90% in complicated skin infections 4

Treatment Duration

• For uncomplicated MRSA skin infections, 5-10 days of therapy is recommended 3, 1
• Treatment should be extended to 7-14 days for complicated infections 2
• Clinical reassessment within 48-72 hours is essential to ensure appropriate response to therapy 2

Special Considerations

• If coverage for both beta-hemolytic streptococci and MRSA is desired, options include clindamycin alone or TMP-SMX/tetracycline in combination with a beta-lactam (e.g., amoxicillin) 3
• The use of rifampin as a single agent or as adjunctive therapy for the treatment of skin infections is not recommended 3
• Recent research suggests that linezolid may be superior to vancomycin for MRSA skin infections, with a clinical success rate of 80.4% vs. 66.7% in patients with vascular disease 6, 7

Prevention of Recurrence

• Keeping draining wounds covered with clean, dry bandages is recommended to prevent recurrence 1, 2
• Maintaining good personal hygiene with regular handwashing is crucial 1
• Consider decolonization with mupirocin (nasal) and chlorhexidine (body) for patients with recurrent MRSA infections 1

Common Pitfalls to Avoid

• Using beta-lactam antibiotics alone is inadequate for MRSA coverage 1
• Failure to drain abscesses when present can lead to treatment failure regardless of antibiotic choice 1
• Topical antibiotics alone are insufficient for treating invasive MRSA infections, though they may be more effective than systemic antibiotics for superficial wound infections 8