What is the recommended treatment for impetigo in the Emergency Department (ED)?

Treatment of Impetigo in the Emergency Department

For impetigo in the Emergency Department setting, topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for limited lesions, while oral antibiotics are recommended for extensive disease or when topical therapy is impractical. 1, 2

Clinical Presentation and Etiology

• Impetigo presents in two forms: nonbullous (70% of cases) and bullous (30% of cases) 3
• Nonbullous impetigo is characterized by honey-colored crusts on face and extremities, caused by Staphylococcus aureus and/or Streptococcus pyogenes 1
• Bullous impetigo presents with thin-roofed vesicopustules that rupture easily, caused exclusively by S. aureus 1

Treatment Algorithm

First-Line Treatment: Topical Antibiotics

• Mupirocin 2% ointment applied three times daily for 5-7 days is highly effective for localized impetigo 2, 4
• Clinical efficacy rates for mupirocin are 71-93%, significantly higher than placebo (35%) 4
• Retapamulin 1% ointment applied twice daily for 5 days is an effective alternative 2
• Topical therapy has shown equal efficacy to oral antibiotics with fewer side effects 5

Second-Line Treatment: Oral Antibiotics

• Oral antibiotics are indicated for:

  • Extensive disease with multiple lesions 1, 2
  • When topical therapy is impractical 2
  • Presence of systemic symptoms 2
  • Outbreaks affecting several people 1

• First-line oral options include:

  • Penicillinase-resistant penicillins (dicloxacillin) 1
  • First-generation cephalosporins (cephalexin) 1, 2

• For penicillin-allergic patients or suspected MRSA:

  • Clindamycin 1
  • Trimethoprim-sulfamethoxazole (not as single agent for cellulitis due to possible streptococcal infection) 1
  • Doxycycline (avoid in children <8 years) 1

Special Considerations

Pediatric Patients

• Mupirocin has demonstrated 78-96% clinical efficacy in pediatric populations 4
• For children with extensive disease requiring systemic therapy:
  • First-generation cephalosporins are first-line 1, 2
  • For suspected MRSA in children <8 years: clindamycin is preferred 1
  • Tetracyclines should not be used in children <8 years 1

MRSA Considerations

• Consider empiric MRSA coverage in areas with high prevalence of community-acquired MRSA 1
• Options for suspected MRSA include:
  • Clindamycin (if local resistance rates are low, <10%) 1
  • Trimethoprim-sulfamethoxazole (note: may not adequately cover streptococcal infections) 1, 3
  • Linezolid (more expensive alternative) 1

Treatment Duration and Follow-up

• Complete the full course of prescribed antibiotics even if symptoms improve quickly 2
• Most cases resolve within 2-3 weeks without scarring 3
• Complications are rare, with poststreptococcal glomerulonephritis being the most serious 3

Common Pitfalls to Avoid

• Failure to consider MRSA in areas with high prevalence 1
• Using penicillin alone, which is seldom effective against S. aureus 3, 6
• Using topical disinfectants, which are inferior to antibiotics and should not be used 3, 6
• Discontinuing treatment prematurely when symptoms improve 2
• Using trimethoprim-sulfamethoxazole as monotherapy when streptococcal infection is suspected 1