Impetigo Treatment Recommendations
Primary Treatment Approach
For localized impetigo with limited lesions, topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment, demonstrating 71% clinical cure rates and 94% pathogen eradication rates. 1, 2
Treatment Algorithm Based on Disease Extent
Limited Disease (Few Lesions, Localized)
- Topical mupirocin 2% ointment three times daily for 5-7 days is the preferred first-line therapy 1, 2
- Retapamulin 1% ointment applied twice daily for 5 days is an FDA-approved alternative for patients aged 9 months or older, covering up to 100 cm² in adults or 2% total body surface area in children 3, 1
- Topical therapy is superior to placebo with an odds ratio of 2.69 and shows weak evidence of superiority over oral erythromycin 4
Extensive Disease (Multiple Sites, Widespread)
- Oral antibiotics for 7 days targeting both S. aureus and S. pyogenes are required when topical therapy is impractical 1, 2
Oral Antibiotic Selection Based on Resistance Patterns
For Methicillin-Susceptible S. aureus (MSSA)
- Dicloxacillin 250 mg four times daily (adults) 1
- Cephalexin 250-500 mg four times daily (adults) with weight-based dosing for children 1, 2
- These agents provide coverage against both S. aureus and S. pyogenes 2
For Suspected or Confirmed MRSA
Empiric MRSA coverage should be initiated in patients with:
- Residence in long-stay care facilities 2, 1
- Hospitalization within preceding 30 days 2
- Failure to respond to first-line therapy after 48-72 hours 1, 2
- Recent antibiotic exposure (beta-lactams, cephalosporins, carbapenems, or quinolones) 2
MRSA-directed oral regimens:
- Clindamycin 300-450 mg three times daily (adults) for 7 days 1
- Doxycycline (adults and children ≥8 years only) 1
- Trimethoprim-sulfamethoxazole covers MRSA but is inadequate for streptococcal infection and should not be used as monotherapy 5
Critical Pitfalls to Avoid
Ineffective Antibiotic Choices
- Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 1
- Topical disinfectants are inferior to antibiotics and should not be used 1, 5
Age-Related Contraindications
- Tetracyclines (doxycycline, minocycline) are contraindicated in children under 8 years of age 1
Resistance Considerations
- 50% of MRSA strains have inducible or constitutive clindamycin resistance 2
- Macrolide resistance in S. pyogenes has increased from 4-5% (1996-1998) to 8-9% (1999-2001), though 99.5% remain susceptible to clindamycin 2
- Mupirocin resistance has been described, though it remains highly effective 2
Treatment Monitoring
Reassessment Timeline
- Re-evaluate patients at 48-72 hours if no improvement occurs 1, 6
- Progression despite antibiotics suggests either resistant organisms or deeper infection than initially recognized 2
When to Escalate Therapy
- Consider MRSA coverage if no response to initial therapy 1
- Patients presenting with severe infection or progression despite empirical therapy should receive vancomycin, linezolid, or daptomycin 2
Infection Control Measures
Preventing Spread
- Keep lesions covered with clean, dry bandages 1, 6
- Maintain good personal hygiene 1
- Wash towels, sheets, combs, and razors daily during treatment 6
Recurrent Impetigo Management
- Three episodes in six months indicates likely S. aureus colonization requiring decolonization 6
- Decolonization regimen: intranasal mupirocin twice daily for 5 days combined with daily dilute bleach baths (1/4-1/2 cup bleach per full bathtub) 6
- Extend decolonization measures to household contacts to reduce recurrence rates 6
Special Populations
Pediatric Dosing
- All oral antibiotic dosing must be adjusted by weight for children 1
- Retapamulin is approved for children aged 9 months or older 3
Immunocompromised or Systemically Ill Patients
- Empiric broad-spectrum antibiotic treatment should be initiated in patients with systemic inflammatory response criteria, signs of organ failure, or immunocompromise 2