What is the recommended treatment for a skin infection?

Treatment of Skin Infections

For skin infections, the recommended first-line treatment depends on the type and severity of infection, with options including incision and drainage for abscesses, topical mupirocin for minor infections, and oral antibiotics such as cephalexin, clindamycin, or trimethoprim-sulfamethoxazole for more extensive infections. 1, 2

Classification and Initial Management

Non-purulent Cellulitis

• For non-purulent cellulitis (no drainage, exudate, or abscess):
  • First-line: Beta-lactam antibiotics targeting streptococci
  • Recommended: Cephalexin 500 mg orally 4 times daily for 5-7 days 1, 2, 3
  • Alternative: Amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days 2

Purulent Skin Infections

• For abscesses and purulent infections:
  • Primary treatment: Incision and drainage 1
  • For small furuncles: Moist heat application may be sufficient 1
  • Empiric antibiotic coverage for CA-MRSA should be added for:
    • Systemic symptoms
    • Extensive or severe local infection
    • Immunocompromised patients
    • Failure to respond to incision and drainage alone 1, 2

Antibiotic Selection

Outpatient Treatment Options

1. MRSA Coverage (Purulent infections):

   • Clindamycin 300-450 mg orally three times daily for 5-7 days 1, 2
   • Trimethoprim-sulfamethoxazole (TMP-SMX) 1, 2
   • Doxycycline 100 mg twice daily for 5-7 days (avoid in children <8 years and pregnant women) 1, 2
   • Linezolid 600 mg orally twice daily 1, 2

2. Streptococcal Coverage (Non-purulent infections):

   • Cephalexin 500 mg orally 3-4 times daily for 5-7 days 2, 3
   • Amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days 2

3. Combined Coverage (when both streptococci and MRSA are concerns):

   • Clindamycin alone 1
   • TMP-SMX or tetracycline plus amoxicillin 1
   • Linezolid alone 1

Hospitalized Patients with Complicated Infections

• Vancomycin IV (first-line) 1, 2
• Linezolid 600 mg IV/PO twice daily 1
• Daptomycin 4 mg/kg IV once daily 1
• Telavancin 10 mg/kg IV once daily 1
• Clindamycin 600 mg IV/PO three times daily 1

Special Populations

Pediatric Patients

• For minor skin infections: Mupirocin 2% topical ointment 1, 4
• For more extensive infections: Cephalexin 25-50 mg/kg/day divided in 4 doses 1, 3
• Avoid tetracyclines in children <8 years due to risk of tooth discoloration 1, 2
• For hospitalized children with complicated infections:
  • Vancomycin IV (first-line) 1
  • Clindamycin 10-13 mg/kg/dose IV every 6-8 hours if local clindamycin resistance is low (<10%) 1

Infections in Damaged Skin

• Irrigation of the wound and debridement of necrotic tissue are critical 1
• For patients with systemic signs of infection or severe comorbidities, broad-spectrum antibiotics covering aerobic and anaerobic organisms are required 1

Treatment Duration

• Standard treatment duration: 5-7 days for most skin infections 1, 2
• Treatment should be individualized based on clinical response 1
• More severe infections may require 10-14 days of treatment 2
• Continue treatment until the patient is afebrile and asymptomatic for at least 48 hours 2

Monitoring and Follow-up

• Patients should be monitored for improvement within 72 hours of starting treatment 2
• Failure to respond after 72 hours should prompt reevaluation 2
• Consider local resistance patterns when selecting empiric therapy 2

Common Pitfalls to Avoid

1. Failing to perform incision and drainage for abscesses
2. Not considering MRSA coverage in areas with high prevalence
3. Using inappropriate dosing (underdosing for severe infections)
4. Continuing antibiotics beyond 7 days for uncomplicated infections
5. Not considering local resistance patterns
6. Using doxycycline in children under 8 years or pregnant women
7. Failing to remove jewelry or foreign bodies that may impede drainage

The treatment of skin infections requires appropriate classification of the infection type, consideration of local resistance patterns, and selection of antibiotics based on likely pathogens. Proper incision and drainage remains the cornerstone of treatment for abscesses, while antibiotic selection should be guided by the clinical presentation and local epidemiology of resistant organisms.