What is the treatment for impetigo?

Treatment for Impetigo

Topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for limited impetigo lesions. 1, 2

First-Line Treatment Options

• Topical antibiotics are recommended for limited impetigo lesions:
  • Mupirocin 2% ointment applied three times daily for 5-7 days 1, 3, 2
  • Retapamulin 1% ointment applied twice daily for 5 days as an effective alternative 1, 3
• Clinical trials have shown topical mupirocin to be as effective as oral antibiotics with fewer side effects, with clinical efficacy rates of 71-93% 2
• Topical antibiotics have been demonstrated to be superior to placebo in meta-analyses (OR = 2.69,95% CI = 1.49 to 4.86) 4

Second-Line Treatment Options

• Oral antibiotics are indicated when:

  • Impetigo is extensive
  • Topical therapy is impractical
  • Topical treatment has failed
  • Systemic symptoms are present 5, 1, 3

• For methicillin-susceptible Staphylococcus aureus (MSSA) and streptococcal infections:

  • Dicloxacillin (250 mg four times daily for adults)
  • Cephalexin (250-500 mg four times daily for adults)
  • First-generation cephalosporins 5, 1, 3

• For suspected methicillin-resistant S. aureus (MRSA):

  • Trimethoprim-sulfamethoxazole (TMP-SMX)
  • Clindamycin (300-450 mg three times daily for adults)
  • Doxycycline (not for children under 8 years) 5, 1, 3

Causative Organisms and Diagnostic Considerations

• Impetigo can be either bullous or nonbullous:

  • Nonbullous impetigo (70% of cases) is caused by S. aureus and/or Streptococcus pyogenes 6
  • Bullous impetigo (30% of cases) is caused exclusively by S. aureus 6

• Cultures of vesicle fluid, pus, or erosions should be obtained if:

  • Treatment fails
  • MRSA is suspected
  • Infections are recurrent 3

Treatment Duration and Follow-up

• Complete the full course of prescribed antibiotics even if symptoms improve quickly 1
• Topical treatment should be used for 5-7 days, and oral antibiotics for 5-10 days 3
• Re-evaluate if no improvement after 48-72 hours of therapy 3

Common Pitfalls and Caveats

• Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 5, 3
• Topical disinfectants are inferior to antibiotics and should not be used 6, 7
• Consider empiric therapy for CA-MRSA in patients at risk for CA-MRSA infection, failure to respond to first-line therapy, or in areas with high local prevalence of CA-MRSA 1
• Oral antibiotic dosing should be adjusted by weight for children, and tetracyclines should not be used in children under 8 years of age 3

Prevention of Spread

• Lesions should be kept covered with clean, dry bandages 3
• Good personal hygiene should be maintained to prevent spread 3
• Systemic antibiotics may be preferred for outbreaks affecting several people to decrease transmission 5