What is the treatment for impetigo in adults?

Treatment of Impetigo in Adults

For adult impetigo, first-line treatment is topical mupirocin or retapamulin for limited disease (less than 100 cm² area), while oral clindamycin is recommended for extensive disease or when topical therapy is impractical, especially given the increasing prevalence of MRSA. 1

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 an 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 1, 2.

Treatment Algorithm

1. Limited Disease (less than 100 cm² area)

First-line: Topical antibiotics

• Mupirocin 2% ointment: Apply three times daily for 5-7 days 1, 3
• Retapamulin 1% ointment: Apply twice daily for 5 days 1, 4
• Fusidic acid: Apply three times daily for 7 days (where available) 1

2. Extensive Disease (greater than 100 cm² area)

First-line: Oral antibiotics

• Clindamycin: 300mg three times daily for 7-10 days 1
  • Excellent coverage against both MRSA and streptococci

Alternative options:

• Cephalexin: First-generation cephalosporin, effective against methicillin-susceptible S. aureus 5, 1
• Trimethoprim-sulfamethoxazole (TMP-SMX): 160-800mg twice daily for 7-10 days
  • Highly effective against MRSA but has inadequate streptococcal coverage
  • Consider combining with a beta-lactam if streptococcal infection is suspected 1
• Doxycycline: 100mg twice daily for 7-10 days 1, 2
• Linezolid: 600mg twice daily for 7-10 days (for severe cases) 1

3. For Penicillin-Allergic Patients

• Clindamycin: 300mg three times daily for 7-10 days
• Erythromycin: If local resistance patterns permit 1, 6
• Doxycycline: 100mg twice daily for 7-10 days 1

Special Considerations

MRSA Concerns

• Community-acquired MRSA (CA-MRSA) is an increasing concern as an etiological agent 1
• For suspected/confirmed MRSA:
  • Topical: Mupirocin or retapamulin remain effective 1, 7
  • Oral: Clindamycin or trimethoprim-sulfamethoxazole 1

Treatment Duration and Follow-up

• Evaluate clinical response within 48-72 hours of starting therapy 1
• Expected resolution within 7-10 days of appropriate treatment 1
• If no improvement within 3-5 days, consider:
  • Obtaining bacterial culture and sensitivity testing
  • Alternative diagnosis
  • Possible need for intravenous antibiotics 1

Prevention and Control

• Keep lesions covered when possible
• Use separate towels and linens
• Practice good hand hygiene
• Systemic therapy is preferred for outbreaks affecting several people to decrease transmission 1

Common Pitfalls to Avoid

1. Failing to consider MRSA as the causative organism in recalcitrant impetigo
2. Using penicillin alone, which has been shown to be inferior for impetigo
3. Inadequate duration of therapy
4. Relying solely on topical therapy for extensive disease
5. Not addressing underlying conditions that may predispose to recurrent infection 1

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

I'm MyMedicalBot, your virtual medical assistant. I provide information but don't replace professional medical advice. Always consult a healthcare provider for personal medical decisions.