Management of Recurrent MRSA Abscesses
For recurrent MRSA abscesses, drain every abscess early and obtain cultures, then treat with a 5-10 day course of TMP-SMX (1-2 double-strength tablets twice daily) or doxycycline (100 mg twice daily), followed by a 5-day decolonization regimen with intranasal mupirocin twice daily, daily chlorhexidine washes, and decontamination of personal items. 1, 2
Immediate Management: Drainage First
- Incision and drainage is the cornerstone of treatment for all recurrent abscesses—antibiotics alone will fail regardless of choice. 1, 2, 3
- Obtain cultures from every recurrent abscess early in the course to guide targeted therapy and identify resistant organisms. 1, 2
- Rule out underlying structural causes including pilonidal cysts, hidradenitis suppurativa, or retained foreign material before assuming simple recurrent infection. 2
Antibiotic Selection for Culture-Proven MRSA
First-Line Oral Therapy (Outpatient)
- TMP-SMX is the preferred first-line oral agent: 1-2 double-strength tablets (160/800 mg) twice daily for adults, based on the strongest evidence. 2
- Doxycycline or minocycline 100 mg twice daily are excellent alternatives, with minocycline often superior when TMP-SMX fails. 1, 2
- Clindamycin 300-450 mg three to four times daily should only be used if local MRSA resistance rates are <10%, as it carries higher risk of Clostridioides difficile infection and inducible resistance. 1, 2, 3
- Treatment duration is 5-10 days depending on clinical response. 1
Intravenous Therapy (Severe/Hospitalized Cases)
Vancomycin 15-20 mg/kg IV every 8-12 hours is the gold standard for hospitalized patients requiring MRSA coverage. 2, 3
- However, vancomycin may have reduced tissue penetration in lower-limb infections (tissue penetration ratio 0.8), potentially contributing to poor outcomes when MRSA MIC >1 μg/mL. 4
- Doses of at least 1 g every 8 hours are needed in critically ill patients to achieve therapeutic trough concentrations of 15-20 mg/L. 5
Linezolid 600 mg IV/PO every 12 hours is equally effective and may be superior for MRSA skin infections, with microbiological cure rates of 87% vs 48% for vancomycin in surgical-site MRSA infections. 2, 3, 6, 7
- Linezolid achieved 79% cure rates in MRSA skin infections compared to 73% for vancomycin in FDA trials. 6
Daptomycin 4-6 mg/kg IV once daily is an alternative bactericidal option. 1, 2, 3
Ceftaroline 600 mg IV every 12 hours is a newer beta-lactam with MRSA activity. 1, 2
Decolonization Strategy: Critical for Preventing Recurrence
Implement a 5-day decolonization regimen including: 1, 2
- Intranasal mupirocin twice daily
- Daily chlorhexidine body washes
- Daily decontamination of personal items (towels, sheets, clothes)
Consider treating household contacts if recurrences persist despite patient decolonization. 2
Special Populations
Pediatric Patients
- TMP-SMX 8-12 mg/kg/day divided twice daily (based on trimethoprim component) is preferred. 1, 2
- Clindamycin 10-13 mg/kg/dose every 6-8 hours if local resistance <10%. 1, 2
- Evaluate patients with early childhood onset for neutrophil disorders. 1, 2
Diabetic Patients
- Diabetic patients have higher risk of treatment failure and often require longer antibiotic courses. 2
- Ensure adequate drainage and consider adjunctive debridement and off-loading. 6
Critical Pitfalls to Avoid
- Never use beta-lactams alone (except ceftaroline)—they have zero activity against MRSA. 3
- Do not use clindamycin if local MRSA resistance exceeds 10% or if inducible resistance is detected. 1, 2, 3
- Do not rely on antibiotics without drainage—this is the most common cause of treatment failure. 2, 3
- Alternative agents may be needed when MRSA MIC >1 μg/mL if using vancomycin, as tissue concentrations may be inadequate. 4, 8