What is the treatment for impetigo?

Treatment of Impetigo

For impetigo treatment, topical antibiotics are the first-line therapy for limited lesions, with mupirocin 2% ointment applied three times daily for 5-7 days being the recommended option. 1, 2

First-Line Treatment: Topical Antibiotics

• Mupirocin 2% ointment should be applied to affected areas three times daily for 5-7 days for limited lesions, as recommended by the American Academy of Pediatrics and the Infectious Diseases Society of America 1
• Retapamulin 1% ointment is an effective alternative, applied twice daily for 5 days 1, 3
• Topical antibiotics have been shown to be more effective than placebo with better cure rates (risk ratio 2.24) 4
• Both mupirocin and retapamulin are FDA-approved for the treatment of impetigo caused by Staphylococcus aureus and Streptococcus pyogenes 2, 3

Second-Line Treatment: Oral Antibiotics

• Oral antibiotics are indicated when:

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

• First-line oral antibiotics include:

  • Dicloxacillin or first-generation cephalosporins (e.g., cephalexin) for methicillin-susceptible S. aureus (MSSA) 1, 5
  • For adults: dicloxacillin 250 mg four times daily or cephalexin 250-500 mg four times daily 5
  • Dosing should be adjusted by weight for children 5

• Studies have shown that topical mupirocin is slightly superior to oral erythromycin (risk ratio 1.07) 4

• Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 5, 6

Special Considerations for MRSA

• Consider empiric therapy for community-acquired MRSA (CA-MRSA) in:

  • Patients at risk for CA-MRSA infection
  • Cases with failure to respond to first-line therapy
  • Areas with high local prevalence of CA-MRSA 1

• For suspected MRSA infections, recommended options include:

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

Treatment Duration and Follow-up

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

Common Pitfalls and Caveats

• Tetracyclines (doxycycline, minocycline) should not be used in children under 8 years of age 5
• Topical disinfectants are inferior to antibiotics and should not be used 4, 7
• Obtain cultures of the vesicle fluid, pus, or erosions if there is treatment failure, MRSA is suspected, or in cases of recurrent infections 5
• Keep lesions covered with clean, dry bandages and maintain good personal hygiene to prevent spread, especially in close-contact settings like military or sports 5, 8
• Worldwide, bacteria causing impetigo show growing resistance rates for commonly used antibiotics, which may influence treatment choices 4

Treatment Algorithm Summary

1. For limited impetigo:

   • Start with topical mupirocin 2% ointment three times daily for 5-7 days 1, 2
   • Alternative: retapamulin 1% ointment twice daily for 5 days 1, 3

2. For extensive disease or when topical therapy is impractical:

   • Use oral antibiotics active against both S. aureus and streptococci 1, 5
   • First choice: dicloxacillin or cephalexin 1
   • For suspected MRSA: clindamycin, trimethoprim-sulfamethoxazole, or doxycycline (age-appropriate) 1, 5

3. For treatment failure:

   • Obtain cultures and adjust therapy based on susceptibility results 5
   • Consider MRSA coverage if not already provided 1, 5