What is the recommended treatment for impetigo?

Treatment of Impetigo

Topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for limited impetigo, while oral antibiotics such as clindamycin or first-generation cephalosporins are recommended for extensive disease. 1, 2

Clinical Presentation and Diagnosis

Impetigo presents in two main forms:

• Nonbullous impetigo (70% of cases):

  • Caused by Staphylococcus aureus or Streptococcus pyogenes
  • Characterized by honey-colored crusts on erythematous base
  • Typically affects face and extremities

• Bullous impetigo (30% of cases):

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

Diagnosis is primarily clinical, based on the characteristic appearance of lesions.

Treatment Algorithm

1. Limited Disease (Few Lesions)

• First-line: Topical mupirocin 2% ointment applied three times daily for 5-7 days 1, 2

  • Clinical efficacy rates of 71-93% demonstrated in clinical studies 2
  • 100% pathogen eradication rate 2
  • Effective against both S. aureus and S. pyogenes 2

• Alternative topical options:

  • Retapamulin
  • Fusidic acid

2. Extensive Disease (Multiple Lesions or Widespread)

• First-line oral options:

  • Clindamycin (300mg three times daily for 7-10 days) - excellent coverage against both MRSA and streptococci 1
  • First-generation cephalosporins (e.g., cephalexin) - good coverage for methicillin-susceptible S. aureus and streptococci 1

• For suspected/confirmed MRSA:

  • Trimethoprim-sulfamethoxazole (160-800mg twice daily for 7-10 days) - highly effective against MRSA but has inadequate streptococcal coverage 1
  • Clindamycin (as above) 1

• For penicillin-allergic patients:

  • Clindamycin (as above)
  • Macrolides (e.g., erythromycin)
  • Doxycycline (100mg twice daily for 7-10 days) - for patients >8 years old 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 obtaining bacterial culture and sensitivity testing
  • Evaluate for alternative diagnosis
  • Consider need for different antibiotic or intravenous therapy 1

Special Considerations

Pediatric Patients

• Mupirocin has demonstrated 78-96% clinical efficacy in pediatric populations 2
• Avoid tetracyclines (doxycycline, minocycline) in children under 8 years due to risk of inhibiting bone growth 1

MRSA Concerns

• Community-acquired MRSA is an increasing concern as an etiological agent 1
• Consider MRSA coverage for recalcitrant cases or in areas with high MRSA prevalence 1, 3

Common Pitfalls to Avoid

1. Inadequate coverage: Using penicillin alone, which has been shown to be inferior for impetigo 1
2. Overlooking MRSA: Failing to consider MRSA in recalcitrant cases 1
3. Insufficient treatment duration: Not completing the full course of antibiotics 1
4. Inappropriate therapy selection: Using topical therapy alone for extensive disease 1
5. Ignoring underlying conditions: Not addressing factors that may predispose to recurrent infection 1

Prevention Measures

• Keep lesions covered when possible
• Use separate towels and linens
• Practice good hand hygiene
• Avoid sharing personal items
• Prompt identification and treatment to prevent spread 1

Complications

Poststreptococcal glomerulonephritis is a rare complication (<1 case/1,000 population per year), though treatment of impetigo has not been shown to prevent this sequela 1.