What is the treatment for impetigo?

Treatment of Impetigo

Topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for localized impetigo, while oral antibiotics are recommended for extensive disease or when topical therapy is impractical. 1

First-Line Treatment for Localized Impetigo

• Topical mupirocin 2% ointment should be applied three times daily for 5-7 days as it has fewer systemic side effects compared to oral antibiotics 1, 2
• Clinical efficacy rates for mupirocin ointment in treating impetigo have been demonstrated to be 71-93% in clinical studies 2
• Retapamulin 1% ointment applied twice daily for 5 days is an effective alternative for limited impetigo 3

When to Use Oral Antibiotics

Oral antibiotics should be used in the following situations:

• When impetigo is extensive or involves multiple sites 1, 3
• When topical therapy is impractical 1
• When treatment with topical antibiotics has failed 3
• When systemic symptoms are present 3

Oral Antibiotic Options

For Methicillin-Susceptible S. aureus (MSSA):

• Dicloxacillin: 250 mg four times daily for adults 1, 3
• Cephalexin: 250-500 mg four times daily for adults 1, 3

For Methicillin-Resistant S. aureus (MRSA):

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

Important Clinical Considerations

• Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 1, 4
• Duration of therapy: 5-7 days for topical treatment and 5-10 days for oral antibiotics 1, 3
• Obtain cultures from lesions if there is treatment failure, MRSA is suspected, or in cases of recurrent infections 1, 3
• Keep lesions covered with clean, dry bandages and maintain good personal hygiene to prevent spread 1
• Re-evaluate if no improvement after 48-72 hours of therapy 1, 3

Special Populations

• For pregnant patients, cephalexin is generally considered safe 1
• For pediatric patients, dosing should be adjusted appropriately:
  • Dicloxacillin: 12 mg/kg/day in 4 divided doses for children 1
  • Avoid tetracyclines (doxycycline, minocycline) in children under 8 years and pregnant women 1, 3

Evidence Strength and Comparative Efficacy

• Studies have shown that topical mupirocin is as effective as oral erythromycin in treating impetigo, with clinical efficacy rates of 93% for mupirocin versus 78.5% for erythromycin 2, 5
• Mupirocin has demonstrated superior bacterial eradication rates compared to oral antibiotics in some studies, particularly for S. aureus 5
• Topical disinfectants are inferior to antibiotics and should not be used for treatment 4, 6

Common Pitfalls to Avoid

• Failing to recognize when impetigo is extensive enough to warrant oral antibiotics 1, 3
• Using penicillin alone, which is ineffective against S. aureus 1, 4
• Not considering local antibiotic resistance patterns when selecting therapy 4
• Not obtaining cultures in cases of treatment failure or suspected MRSA 1, 3
• Discontinuing treatment prematurely before the recommended duration 1, 3