What is the treatment for impetigo?

Impetigo Treatment

For impetigo, topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for localized infections, while oral antibiotics such as clindamycin (300mg three times daily for 7-10 days) are recommended for extensive disease. 1

Types of Impetigo

• Nonbullous impetigo (70% of cases)

  • Caused by Staphylococcus aureus or Streptococcus pyogenes
  • Presents with honey-colored crusts on erythematous base
  • Typically affects face and extremities 1, 2

• Bullous impetigo (30% of cases)

  • Caused exclusively by S. aureus
  • Presents with large, flaccid bullae
  • More likely to affect intertriginous areas 1, 2

Treatment Algorithm

1. Localized Infection (Limited Lesions)

• First-line: Topical antibiotics
  • Mupirocin 2% ointment applied three times daily for 5-7 days 1, 3
    • Clinical efficacy rates of 71-93% in clinical studies 3
    • 94-100% pathogen eradication rates 3
    • Effective against both S. aureus and S. pyogenes 3
  • Alternative topicals: retapamulin or fusidic acid 1

2. Extensive Disease (Multiple Lesions or Widespread)

• Oral antibiotics for 7-10 days:

  • First-line options:

    • Clindamycin (300mg three times daily) - excellent coverage against MRSA and streptococci 1
    • First-generation cephalosporins like cephalexin 1
    • Amoxicillin/clavulanate 1

  • For penicillin-allergic patients:

    • Clindamycin
    • Macrolides (erythromycin)
    • Doxycycline (for patients >8 years old) 1

  • For suspected/confirmed MRSA:

    • Clindamycin
    • Trimethoprim-sulfamethoxazole (160-800mg twice daily) - note: inadequate streptococcal coverage 1

Special Considerations

Pediatric Patients

• Mupirocin has shown 78-96% clinical efficacy in pediatric populations 3
• Avoid tetracyclines (doxycycline, minocycline) in children under 8 years due to risk of inhibiting bone growth 1
• For hospitalized children with complicated infections, vancomycin is first choice, followed by clindamycin and linezolid 1

Treatment Duration and Response

• Typical duration: 5-7 days for topical therapy, 7-10 days for oral therapy 1
• Evaluate clinical response within 48-72 hours of starting therapy 1
• If no improvement within 3-5 days:
  • Consider bacterial culture and sensitivity testing
  • Evaluate for alternative diagnosis
  • Consider need for intravenous antibiotics 1

Prevention and Hygiene Practices

• Keep lesions covered when possible
• Use separate towels and linens
• Practice good hand hygiene
• Avoid sharing personal items
• Limit exposure to infected individuals 1

Common Pitfalls to Avoid

1. Failure to consider MRSA in recalcitrant cases 1
2. Using penicillin alone, which is inferior to other antibiotics for impetigo 1, 4
3. Inadequate treatment duration 1
4. Relying solely on topical therapy for extensive disease 1
5. Using topical disinfectants, which are inferior to antibiotics 2, 5
6. Not addressing underlying conditions that may predispose to recurrent infection 1
7. Using trimethoprim-sulfamethoxazole alone when streptococcal infection is suspected (inadequate coverage) 1

Remember that impetigo typically resolves within 7-10 days with appropriate treatment, and complications such as poststreptococcal glomerulonephritis are rare (<1 case/1,000 population per year) 1.