What is the initial treatment for a skin infection?

Initial Treatment for Skin Infections

For uncomplicated skin infections, oral antibiotics targeting Staphylococcus aureus and Streptococcus species are the first-line treatment, with clindamycin, trimethoprim-sulfamethoxazole (TMP-SMX), or a tetracycline being the preferred options for empiric coverage of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). 1

Classification and Assessment

Before selecting treatment, it's important to classify the infection:

• Uncomplicated/Simple Infections: Impetigo, folliculitis, furuncles, small abscesses
• Complicated Infections: Deeper tissue involvement, surgical/traumatic wound infections, major abscesses, cellulitis

Key assessment points:

• Presence of purulence (indicates likely S. aureus)
• Extent of erythema (>5cm suggests more severe infection)
• Systemic symptoms (fever >38.5°C, tachycardia >110 bpm)
• Risk factors for MRSA (prior MRSA infection, recent antibiotic use)

Treatment Algorithm

1. Uncomplicated Skin Infections (Outpatient)

For purulent infections (abscess, furuncle, carbuncle):

• Primary treatment: Incision and drainage 1
• Antibiotic options (if systemic symptoms, extensive disease, or immunocompromised):
  • Clindamycin 300-450mg PO every 6-8 hours 1, 2
  • TMP-SMX 1-2 DS tablets twice daily 1
  • Doxycycline or minocycline 100mg twice daily 1

For non-purulent infections (cellulitis, erysipelas):

• Primary treatment: Beta-lactam antibiotics
  • Cephalexin 500mg PO every 6 hours for 5-7 days 3, 4
  • Dicloxacillin 500mg PO every 6 hours 4
  • Amoxicillin-clavulanate for periorbital cellulitis 5

If both streptococcal and MRSA coverage needed:

• Clindamycin alone (covers both) 1
• OR TMP-SMX/tetracycline plus amoxicillin 1

2. Complicated Skin Infections (Inpatient)

For hospitalized patients with complicated infections:

• Surgical debridement is essential for abscesses and necrotizing infections 1
• Empiric antibiotic options:
  • Vancomycin IV 15mg/kg every 12 hours 1
  • Linezolid 600mg IV/PO twice daily 1
  • Daptomycin 4mg/kg IV once daily 1
  • Telavancin 10mg/kg IV once daily 1

For mixed infections (gram-positive and gram-negative/anaerobic):

• Piperacillin-tazobactam 3.375g every 6h or 4.5g every 8h IV 1
• Imipenem-cilastatin 500mg every 6h IV 1
• Meropenem 1g every 8h IV 1
• Ertapenem 1g every 24h IV 1

Duration of Therapy

• Uncomplicated infections: 5-7 days 5
• Complicated infections: 7-14 days, individualized based on clinical response 1

Special Considerations

Pediatric Patients

• For minor skin infections: Mupirocin 2% topical ointment 1
• Avoid tetracyclines in children <8 years 1
• For hospitalized children with complicated infections: Vancomycin or clindamycin 10-13mg/kg/dose IV every 6-8 hours 1

Diabetic Patients

• More aggressive treatment may be needed
• Consider broader spectrum coverage
• Optimize glycemic control 5

Recurrent Infections

• Keep draining wounds covered with clean, dry bandages
• Maintain good personal hygiene
• Avoid sharing personal items (razors, towels)
• Consider decolonization strategies for recurrent MRSA 1

Important Caveats

• Obtain cultures from abscesses and purulent infections before starting antibiotics, especially in patients with severe local infection, systemic illness, or treatment failure 1
• Avoid rifampin as a single agent or adjunctive therapy for skin infections 1
• Monitor for treatment failure: Lack of improvement within 48-72 hours suggests need for reevaluation 5
• Watch for diarrhea with clindamycin use; discontinue if significant diarrhea occurs 2

The choice of empiric therapy should be guided by local resistance patterns, with adjustment based on culture results when available.