What is the treatment for impetigo?

Treatment of Impetigo

Topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for localized impetigo, while oral antibiotics are recommended for extensive disease or when topical therapy is impractical. 1, 2

First-Line Treatment for Localized Impetigo

• Topical therapy is preferred for limited disease due to fewer systemic side effects 1
• Mupirocin 2% ointment applied three times daily for 5-7 days is the preferred topical treatment with clinical efficacy rates of 71-93% 1, 3
• Retapamulin 1% ointment applied twice daily for 5 days is an effective alternative for limited impetigo 2
• Clinical studies have shown topical mupirocin to be as effective as oral erythromycin in treating impetigo, with superior eradication of S. aureus 4

When to Use Oral Antibiotics

• Oral antibiotics should be used when: 1, 2
  • Impetigo is extensive or involves multiple sites
  • Topical therapy is impractical
  • Treatment with topical antibiotics has failed
  • Systemic symptoms are present

Oral Antibiotic Options

• For Methicillin-Susceptible S. aureus (MSSA): 1, 2

  • Dicloxacillin: 250 mg four times daily for adults
  • Cephalexin: 250-500 mg four times daily for adults

• For Methicillin-Resistant S. aureus (MRSA): 1, 2

  • Clindamycin: 300-450 mg three times daily for adults
  • Trimethoprim-sulfamethoxazole (TMP-SMX)
  • Doxycycline (not for children under 8 years)

Important Clinical Considerations

• Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 1, 5
• Duration of therapy: 5-7 days for topical treatment and 5-10 days for oral antibiotics 1, 2
• Obtain cultures from lesions if there is treatment failure, MRSA is suspected, or in cases of recurrent infections 1, 2
• Keep lesions covered with clean, dry bandages and maintain good personal hygiene to prevent spread 1
• Re-evaluate if no improvement after 48-72 hours of therapy 1, 2

Special Populations

• For pediatric patients: 1, 2

  • Dosing should be adjusted appropriately (e.g., dicloxacillin: 12 mg/kg/day in 4 divided doses)
  • Avoid tetracyclines (doxycycline, minocycline) in children under 8 years

• For pregnant patients: 1

  • Cephalexin is generally considered safe
  • Avoid tetracyclines

Treatment Algorithm

1. Assess extent of disease: 1, 2

   • Localized (few lesions): Use topical therapy
   • Extensive (multiple lesions): Use oral antibiotics

2. For localized impetigo: 1, 3

   • Apply mupirocin 2% ointment three times daily for 5-7 days

3. For extensive impetigo: 1, 2

   • Prescribe appropriate oral antibiotic based on suspected pathogen
   • Consider local resistance patterns when selecting therapy

4. Follow-up: 1, 2

   • If no improvement after 48-72 hours, reassess and consider culture
   • Consider alternative diagnosis if not responding to appropriate therapy

Common Pitfalls and Caveats

• Topical disinfectants are inferior to antibiotics and should not be used 6
• Increasing prevalence of antibiotic-resistant bacteria may affect treatment success 5
• Mupirocin resistance has been documented, which may necessitate alternative treatments 5
• Impetigo usually resolves within 2-3 weeks without scarring, but treatment helps prevent spread and complications 5