What is the treatment for Methicillin-resistant Staphylococcus aureus (MRSA) skin infections?

Treatment of MRSA Skin Infections

For MRSA skin infections, first-line treatment includes oral antibiotics such as trimethoprim-sulfamethoxazole (TMP-SMX), doxycycline, or clindamycin, along with incision and drainage of any abscesses. 1

First-Line Treatment Options

Outpatient Management

• Incision and drainage is essential for purulent lesions
• Oral antibiotic options:
  • Trimethoprim-sulfamethoxazole (TMP-SMX): 1-2 double-strength tablets (160mg/800mg) twice daily
  • Doxycycline: 100 mg twice daily (not recommended for children under 8 years)
  • Clindamycin: 300-450 mg three times daily (effective against both MRSA and streptococci)
  • For pediatric patients ≤45 kg: doxycycline 2 mg/kg/dose every 12 hours 1

Treatment Duration

• Uncomplicated skin infections: 5-10 days
• Complicated skin infections: 7-14 days 1

Alternative Treatment Options

For Treatment Failures or Severe Infections

• Linezolid: 600 mg orally twice daily 1, 2

  • FDA-approved for acute bacterial skin and skin structure infections (ABSSSI) caused by MRSA
  • Particularly effective for treatment failures
  • Clinical cure rates of 79% for MRSA skin infections 2

• Tedizolid: 200 mg once daily for 6 days 3

  • FDA-approved for ABSSSI caused by MRSA in patients 12 years and older
  • Can be administered orally or intravenously
  • Shorter treatment duration (6 days) compared to other options

For Hospitalized Patients

• Vancomycin: 15-20 mg/kg/dose every 8-12 hours IV

  • Loading dose of 25-30 mg/kg for serious infections
  • Target trough concentrations of 15-20 μg/mL 1

• Daptomycin: Dosage determined by healthcare professional

  • Particularly useful for MRSA bacteremia with skin manifestations 1

Supportive Care Measures

• Elevation of affected limb to promote drainage of edema
• Proper wound care, including cleansing and debridement of necrotic tissue
• Regular assessment of clinical response within 48-72 hours 1

Management Algorithm

1. Assess severity:

   • Localized infection vs. systemic symptoms
   • Presence of abscess vs. cellulitis
   • Patient risk factors (immunocompromised, etc.)

2. For localized abscess:

   • Perform incision and drainage
   • Consider antibiotic therapy based on size, location, and patient factors

3. For cellulitis or post-drainage therapy:

   • Start empiric oral antibiotic (TMP-SMX, doxycycline, or clindamycin)
   • Reassess in 48-72 hours

4. If no improvement:

   • Reassess diagnosis
   • Check culture results if available
   • Consider alternative antibiotic (linezolid or tedizolid)
   • Evaluate for hospitalization if worsening

5. For severe infections:

   • Hospitalize for IV antibiotics (vancomycin or daptomycin)
   • Consider surgical consultation

Prevention of Recurrence and Spread

• Cover draining wounds with clean, dry bandages
• Regular hand hygiene with soap and water or alcohol-based hand gel
• Avoid sharing personal items that contact skin
• Consider decolonization for recurrent infections:
  • Nasal mupirocin twice daily for 5-10 days
  • Chlorhexidine body washes for 5-14 days or dilute bleach baths 1

Common Pitfalls to Avoid

• Failure to drain abscesses: Antibiotics alone are often insufficient for purulent collections
• Inadequate follow-up: Assess clinical response within 48-72 hours
• Inappropriate antibiotic selection: Consider local resistance patterns
• Insufficient treatment duration: Complete the full course of antibiotics
• Neglecting decolonization: Consider for recurrent infections
• Overlooking household contacts: Evaluate close contacts for evidence of infection to prevent spread 1