What is the treatment for impetigo?

Treatment of Impetigo

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

Treatment Algorithm

First-Line Treatment: Topical Antibiotics

• Mupirocin 2% ointment should be applied to affected areas three times daily for 5-7 days for limited lesions 1, 2
• Retapamulin 1% ointment is an effective alternative, applied twice daily for 5 days 1, 3
• Clinical studies have shown mupirocin to be highly effective with cure rates of 71-93% in evaluable populations 2
• Topical antibiotics have been shown to be superior to placebo with a pooled risk ratio of 2.24 4

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, 3
• First-line oral options include:
  • Dicloxacillin (250 mg four times daily for adults)
  • Cephalexin (250-500 mg four times daily for adults) 1, 3
• Topical mupirocin has been shown to be slightly superior to oral erythromycin (pooled RR 1.07) 4
• Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 3, 5

Special Considerations

MRSA Coverage

• In areas with high prevalence of community-acquired MRSA (CA-MRSA), or for patients at risk for CA-MRSA infection, consider:
  • Clindamycin (300-450 mg three times daily for adults)
  • Trimethoprim-sulfamethoxazole (TMP-SMX)
  • Doxycycline (not for children under 8 years) 1, 3
• Obtain cultures if there is treatment failure, MRSA is suspected, or in cases of recurrent infections 3

Pediatric Considerations

• Adjust oral antibiotic dosing by weight for children 3
• Avoid tetracyclines (doxycycline, minocycline) in children under 8 years of age 3
• Clinical studies have shown mupirocin to be effective in pediatric populations with efficacy rates of 78-96% 2

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
• Keep lesions covered with clean, dry bandages and maintain good personal hygiene to prevent spread 3

Common Pitfalls and Caveats

• Side effects are more common with oral antibiotics than topical treatments, with gastrointestinal effects being most common 4
• Bacterial resistance is an increasing concern, with methicillin-resistant S. aureus, macrolide-resistant streptococcus, and mupirocin-resistant streptococcus all documented 5
• Topical disinfectants are inferior to antibiotics and should not be used 5, 4
• Impetigo is highly contagious, especially in close-contact settings like schools, sports teams, or military units 6