What is the treatment for impetigo?

Treatment for Impetigo

For impetigo treatment, topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line therapy for limited disease, while oral clindamycin (300mg three times daily for 7-10 days) is recommended for extensive disease or when topical therapy is impractical. 1

Treatment Algorithm

Step 1: Assess Extent of Disease

• Limited disease (few lesions in a localized area):
  • Use topical therapy
• Extensive disease (multiple lesions, widespread areas):
  • Use oral antibiotics
  • Consider oral therapy for outbreaks affecting multiple people to decrease transmission 1

Step 2: First-Line Treatment Options

For Limited Disease:

• Topical mupirocin 2% ointment applied three times daily for 5-7 days 1, 2
  • Clinical efficacy rates of 71-93% in clinical studies 2
  • Effective against both Staphylococcus aureus and Streptococcus pyogenes 1, 2
  • Comparable efficacy to oral erythromycin with fewer side effects 2

For Extensive Disease:

• Oral antibiotics for 7-10 days 1:
  • Clindamycin (300mg three times daily) - excellent coverage against MRSA and streptococci 1
  • First-generation cephalosporins like cephalexin 1
  • Penicillinase-resistant semisynthetic penicillins 1

Step 3: Alternative Options

For Penicillin-Allergic Patients:

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

For Suspected/Confirmed MRSA:

• Trimethoprim-sulfamethoxazole (160-800mg twice daily for 7-10 days)
  • Note: Has inadequate streptococcal coverage; may need to combine with a beta-lactam if streptococcal infection is suspected 1
• Clindamycin (as above) 1

Other Topical Options:

• Retapamulin
• Fusidic acid 1, 3

Important Clinical Considerations

Types of Impetigo

• Nonbullous impetigo (70% of cases):
  • Caused by S. aureus or S. pyogenes
  • Presents with honey-colored crusts on face and extremities 1, 3
• Bullous impetigo (30% of cases):
  • Caused exclusively by S. aureus
  • Presents with large, flaccid bullae, often in intertriginous areas 1, 3

Monitoring Response

• 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 different antibiotics 1

Common Pitfalls to Avoid

1. Failure to consider MRSA in recalcitrant cases 1
2. Using penicillin alone, which has been shown to be inferior for impetigo 1, 4
3. Inadequate duration of therapy 1
4. Relying solely on topical therapy for extensive disease 1
5. Using tetracyclines in children under 8 years due to risk of inhibiting bone growth 1
6. Using topical disinfectants, which are inferior to antibiotics and should not be used 3, 5

Prevention Measures

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

Special Populations

• Children: Mupirocin has shown 78-96% efficacy in pediatric populations 2
• Hospitalized children with complicated infections: Consider vancomycin as first choice, followed by clindamycin and linezolid 1

The treatment approach has evolved with increasing prevalence of antibiotic-resistant bacteria, including methicillin-resistant S. aureus (MRSA), macrolide-resistant streptococcus, and mupirocin-resistant streptococcus 3. Therefore, empiric therapy should consider local resistance patterns when available.