What is the recommended treatment for bullous impetigo?

Treatment of Bullous Impetigo

For bullous impetigo, topical mupirocin or retapamulin applied twice daily for 5 days is the recommended first-line treatment for limited disease, while oral antibiotics active against Staphylococcus aureus should be used for extensive disease or outbreaks. 1

Causative Organism

• Bullous impetigo is caused exclusively by Staphylococcus aureus strains that produce toxins cleaving the dermal-epidermal junction, forming fragile, thin-roofed vesicopustules 1, 2
• The lesions appear as flaccid bullae that may rupture, creating crusted, erythematous erosions 2

Treatment Recommendations

For Limited Disease

• Topical antibiotics are the first-line treatment for limited bullous impetigo 1, 3:
  • Mupirocin 2% ointment applied twice daily for 5 days 1, 3
  • Retapamulin applied twice daily for 5 days 1
• Clinical efficacy rates for mupirocin are significantly higher than placebo (71% vs 35%) 3
• Mupirocin has shown similar or slightly superior efficacy compared to oral antibiotics in clinical trials 3, 4

For Extensive Disease

• Oral antibiotics are recommended for patients with numerous lesions or during outbreaks affecting multiple people 1, 5
• A 7-day regimen with an agent active against S. aureus is recommended 5, 1
• For methicillin-susceptible S. aureus (MSSA):
  • Dicloxacillin or cephalexin are the preferred agents 5, 1
• For suspected or confirmed methicillin-resistant S. aureus (MRSA):
  • Doxycycline, clindamycin, or sulfamethoxazole-trimethoprim (SMX-TMP) are recommended 5, 1
• Penicillin V is seldom effective and should not be used 2, 6

Special Considerations

• Topical disinfectants are inferior to antibiotics and should not be used 2, 4
• Monitor for clinical response within 24-48 hours when using oral antibiotics 1
• If progression occurs despite antibiotics, consider:
  • Infection with resistant organisms 1, 2
  • Presence of a deeper, more serious infection than initially recognized 1
• Systemic antimicrobials should be used during outbreaks of post-streptococcal glomerulonephritis to eliminate nephritogenic strains from the community 5
• Resistance patterns should be considered when selecting empiric therapy, as there are increasing rates of resistance to commonly used antibiotics 2, 4

Treatment Algorithm

1. Assess extent of disease:

   • Limited disease (few lesions): Use topical antibiotics 1, 3
   • Extensive disease (numerous lesions) or outbreaks: Use oral antibiotics 5, 1

2. For limited disease:

   • Apply mupirocin 2% ointment or retapamulin twice daily for 5 days 1, 3

3. For extensive disease:

   • Prescribe oral antibiotics for 7 days 5, 1
   • For MSSA: dicloxacillin or cephalexin 5, 1
   • For suspected/confirmed MRSA: doxycycline, clindamycin, or SMX-TMP 5, 1

4. If no improvement within 48 hours:

   • Reassess diagnosis and consider culture and sensitivity testing 1
   • Consider changing antibiotic based on local resistance patterns 2, 4