What is the recommended treatment for a patient with impetigo?

Impetigo Treatment

First-Line Treatment: Topical Mupirocin

For limited impetigo lesions, topical mupirocin 2% ointment applied three times daily for 5-7 days is the recommended first-line treatment, demonstrating 71-93% clinical efficacy and superior pathogen eradication compared to placebo. 1, 2

• Mupirocin is FDA-approved specifically for impetigo caused by Staphylococcus aureus and Streptococcus pyogenes 2
• Clinical trials demonstrate mupirocin achieves 94-100% pathogen eradication rates 2
• Mupirocin is equally effective as oral erythromycin but with fewer adverse effects 3
• Do not use bacitracin or neomycin—they are considerably less effective and should be avoided 1

When to Switch to Oral Antibiotics

Transition to oral antibiotics if: 1

• Extensive disease (multiple lesions or large affected areas)
• No improvement after 3-5 days of topical therapy
• Lesions on face, eyelid, or mouth
• Systemic symptoms present
• Need to limit spread to others

Oral Antibiotic Selection

For Presumed Methicillin-Susceptible S. aureus (MSSA):

First-line oral options: 1, 4

• Dicloxacillin 250 mg four times daily (adults) or 12 mg/kg/day in 4 divided doses (children)
• Cephalexin 250-500 mg four times daily (adults) or 25 mg/kg/day in 4 divided doses (children)
• Amoxicillin-clavulanate 875/125 mg twice daily (adults) or 25 mg/kg/day in 2 divided doses (children)

For Suspected or Confirmed MRSA:

Recommended MRSA-active agents: 1, 4

• Clindamycin 300-450 mg three times daily (adults) or 10-20 mg/kg/day in 3 divided doses (children)
• Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily (adults) or 8-12 mg/kg/day in 2 divided doses (children)
• Doxycycline 100 mg twice daily (adults only—avoid in children <8 years)

Duration of oral therapy: 5-10 days 1

Critical Treatment Pitfalls to Avoid

• Never use penicillin alone—it lacks adequate S. aureus coverage and is ineffective for impetigo 1, 4
• Avoid topical clindamycin cream—it is FDA-approved only for acne, not impetigo, and has insufficient bioavailability 1
• Macrolides (erythromycin) have increasing resistance rates and should be used with caution 4
• Topical disinfectants are inferior to antibiotics and should not be used 5, 6

Treatment Failure Management

If mupirocin fails after 3-5 days: 4

• Initiate oral antibiotics (dicloxacillin, cephalexin, clindamycin, or amoxicillin-clavulanate)
• Consider mupirocin resistance, especially in high MRSA prevalence areas
• Obtain cultures to identify pathogen and susceptibilities
• Reassess for deeper infection or alternative diagnosis if no improvement after 48-72 hours of oral therapy

For recurrent impetigo, consider decolonization strategies for S. aureus carriers 4

Special Population Considerations

Pediatric Patients:

• Avoid tetracyclines (including doxycycline) in children under 8 years 1, 4
• Clindamycin 10-20 mg/kg/day in 3 divided doses is preferred for MRSA in children 4
• TMP-SMX 8-12 mg/kg/day in 2 divided doses is an alternative for pediatric MRSA 4

Pregnant Patients:

• Cephalexin is considered safe during pregnancy 1, 4
• Avoid tetracyclines 1

Prevention of Spread

• Keep lesions covered with clean, dry bandages 1
• Maintain good hand hygiene with regular handwashing 1
• Avoid sharing personal items that contact the skin 1

Culture Indications

Obtain cultures from lesions when: 1

• Treatment failure occurs
• MRSA is suspected
• Recurrent infections present