What is the treatment for a skin infection?

Treatment of Skin Infections

The treatment of skin infections should be tailored to the specific type of infection, with antibiotics targeting Gram-positive bacteria (particularly Staphylococcus aureus and Streptococcus species) as the mainstay of therapy for most skin infections. 1

Classification and Initial Management

Superficial Infections

• Impetigo:

  • Topical mupirocin for localized, non-bullous impetigo 1
  • Oral antibiotics against Gram-positive bacteria for more extensive cases 1

• Erysipelas and Cellulitis:

  • Oral antibiotics against Gram-positive bacteria 1
  • Consider empiric MRSA coverage for patients at risk or non-responders to first-line therapy 1
  • Elevation of affected area to promote drainage of edema 1

• Superficial Abscesses:

  • Incision and drainage is the primary treatment 1
  • Antibiotics generally not needed for simple, adequately drained abscesses 1

Necrotizing Infections

• Necrotizing Fasciitis:
  • Surgical debridement is essential 1
  • Broad-spectrum antibiotics (see table below) 1
  • Early aggressive treatment is critical to reduce mortality 1

Antibiotic Selection

First-Line Antibiotics for Common Skin Infections:

Type of Infection	First-Line Antibiotic	Alternative Options
Impetigo	Topical mupirocin or oral anti-staphylococcal antibiotics	Oral cephalexin, dicloxacillin
Erysipelas/Cellulitis	Penicillin V or first-generation cephalosporin	Clindamycin, macrolides if penicillin-allergic
MRSA Infections	Trimethoprim-sulfamethoxazole, doxycycline, or clindamycin	Vancomycin, linezolid, daptomycin (for severe cases)
Mixed/Necrotizing Infections	Piperacillin-tazobactam plus vancomycin or carbapenem	Imipenem, meropenem, ertapenem

Dosing for Common Antibiotics:

• Clindamycin: 300-450 mg every 6 hours for adults; 8-20 mg/kg/day divided into 3-4 doses for children 2
• Penicillin V: 500 mg four times daily for 7-10 days 1
• Vancomycin: 15 mg/kg IV every 12 hours 3

Special Considerations

MRSA Infections

• Consider MRSA coverage when:
  • Local MRSA prevalence is high
  • Patient has risk factors (prior MRSA infection, recent hospitalization, etc.)
  • No response to initial therapy 1, 3, 4
• Options include:
  • Trimethoprim-sulfamethoxazole (not for streptococcal infections)
  • Doxycycline (for patients ≥2 years old)
  • Clindamycin (if local resistance rates are low)
  • Vancomycin for severe infections 1, 4

Duration of Therapy

• Uncomplicated infections: 5-10 days
• Complicated infections: 10-14 days
• Necrotizing infections: 2-3 weeks 3
• For β-hemolytic streptococcal infections: minimum 10 days 2

Follow-up

• Reassess after 48-72 hours of treatment to evaluate response 3
• Consider repeat cultures if no improvement 3

Prevention of Recurrent Infections

• Address underlying conditions (tinea pedis, venous eczema, lymphedema) 1
• Keep skin well hydrated with emollients 1
• For frequent recurrences, consider prophylactic antibiotics:
  • Monthly intramuscular benzathine penicillin 1.2 MU
  • Oral erythromycin 250 mg twice daily
  • Oral penicillin V 1 g twice daily 1

Common Pitfalls to Avoid

1. Failing to drain abscesses: Incision and drainage is the primary treatment for abscesses; antibiotics alone are often insufficient 1
2. Overlooking MRSA: Consider local resistance patterns when selecting empiric therapy 5, 4
3. Inappropriate antibiotic use: Simple drained abscesses often don't require antibiotics 3
4. Neglecting elevation of affected limbs: Important for reducing edema and improving outcomes 1
5. Inadequate debridement: For necrotizing infections, thorough surgical debridement is essential 3

By following these evidence-based guidelines and considering the specific type of skin infection, most patients can be effectively treated with appropriate antibiotics and supportive care.