What are the treatment options for skin staph infections?

Treatment Options for Skin Staph Infections

For skin staph infections, the primary treatment approach includes incision and drainage for abscesses, with antibiotic selection based on methicillin susceptibility, with β-lactams for MSSA and trimethoprim-sulfamethoxazole, doxycycline, or clindamycin for MRSA. 1

Classification and Initial Management

Superficial Infections

• Impetigo: Discrete purulent lesions caused by β-hemolytic Streptococcus and/or S. aureus

  • Topical mupirocin 2% ointment is indicated for localized, non-bullous impetigo 2, 3
  • For widespread impetigo: oral antibiotics effective against Gram-positive bacteria 2

• Abscesses and Boils:

  • Primary treatment is incision and drainage 2, 1
  • Antibiotics generally not recommended for simple, drained abscesses 2
  • Culture wound for identification of causative agent and antimicrobial susceptibility 2

• Cellulitis/Erysipelas:

  • Require antibiotic therapy against Gram-positive bacteria 2
  • Cannot be drained; require systemic antibiotics 1

Antibiotic Selection Based on Methicillin Susceptibility

For Methicillin-Susceptible S. aureus (MSSA):

1. First-line: β-lactam antibiotics 1, 4

   • Penicillinase-resistant penicillins (flucloxacillin, dicloxacillin)
   • Cephalexin (FDA-approved for skin infections caused by S. aureus) 5

2. For penicillin-allergic patients (non-anaphylactic):

   • First-generation cephalosporins (cefazolin, cephalexin) 1, 4

3. For immediate penicillin hypersensitivity:

   • Clindamycin or lincomycin 1, 4
   • Erythromycin (though resistance is increasing) 4

For Methicillin-Resistant S. aureus (MRSA):

1. Outpatient/mild infections:

   • Trimethoprim-sulfamethoxazole 1
   • Doxycycline or minocycline (safe in children >2 years for <2 weeks) 2, 1
   • Clindamycin (if local resistance <10%) 1

2. Severe infections:

   • Vancomycin IV (first-line for serious MRSA) 1, 4
   • Teicoplanin IV (for vancomycin-allergic patients) 4
   • Linezolid (for children >12 years: 600 mg PO twice daily; <12 years: 10 mg/kg PO every 8 hours) 1

Duration of Therapy

• Uncomplicated skin infections: 5-10 days 1
• Complicated skin infections: 7-14 days 2, 1
• Response to therapy expected within first few days 6

Special Considerations

Community-Acquired vs. Hospital-Acquired MRSA

• Community-acquired MRSA often remains susceptible to non-β-lactam antibiotics 2, 6
• Hospital-acquired MRSA typically multi-resistant, may require combination therapy 4

Prevention of Recurrent Infections

• Decolonization protocol for recurrent infections 1:
  • Chlorhexidine body washes daily for 5-14 days
  • Nasal mupirocin (twice daily for 5-7 days) for carriers
  • Laundering clothing, towels, bedding in hot water
  • Avoid sharing personal items

Wound Management

• Proper wound care is essential alongside antibiotic therapy 1
• For draining wounds: packing with appropriate dressing materials
• For infected wounds with necrotic tissue: debridement before antibiotic therapy
• Obtain cultures before starting antibiotics when possible 1

Pitfalls to Avoid

1. Using trimethoprim-sulfamethoxazole as single agent for cellulitis (may miss group A Streptococcus) 2
2. Failing to drain abscesses (antibiotics alone often insufficient) 2
3. Using vancomycin for β-lactam-susceptible S. aureus (higher failure rates) 1
4. Using single-agent therapy for multi-resistant MRSA (rapid resistance development) 4
5. Neglecting local resistance patterns when selecting empiric therapy 1

The most recent evidence emphasizes the importance of proper wound cultures to guide therapy, appropriate incision and drainage for abscesses, and selection of antibiotics based on local resistance patterns and methicillin susceptibility of the infecting strain.