What is the treatment for impetigo (impetigo tx)?

Treatment of Impetigo

For limited impetigo, start with topical mupirocin 2% ointment applied three times daily for 5-7 days; for extensive disease involving multiple sites or when topical therapy is impractical, use oral antibiotics for 7 days targeting both S. aureus and streptococci. 1, 2

First-Line Treatment for Limited Disease

• Topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for localized impetigo 1, 2, 3
• Retapamulin 1% ointment applied twice daily for 5 days is an effective alternative for limited disease 1
• The FDA confirms mupirocin's efficacy with clinical cure rates of 71% versus 35% for placebo, and 93% efficacy in head-to-head comparison with oral erythromycin 3

When to Use Oral Antibiotics

Oral antibiotics are indicated when: 1, 2

• Impetigo is extensive or involves multiple sites
• Topical therapy is impractical
• Treatment with topical antibiotics has failed
• Systemic symptoms are present
• Outbreaks affect several people (to decrease transmission)

Oral Antibiotic Regimens

For Methicillin-Susceptible S. aureus (MSSA):

• Dicloxacillin 250 mg four times daily for adults 1, 2
• Cephalexin 250-500 mg four times daily for adults 1, 2
• Treatment duration: 7 days 2

For Methicillin-Resistant S. aureus (MRSA):

• Clindamycin 300-450 mg three times daily for adults 1, 2
• Trimethoprim-sulfamethoxazole (TMP-SMX) - note this provides inadequate streptococcal coverage 1, 2, 4
• Doxycycline (not for children under 8 years) 1, 2

Critical Pitfalls to Avoid

• Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 1
• TMP-SMX covers MRSA but is inadequate for streptococcal infection, so consider combination therapy or alternative agents when streptococcal infection cannot be excluded 4
• Topical disinfectants are inferior to antibiotics and should not be used 5, 6

When to Obtain Cultures

Obtain cultures of vesicle fluid, pus, or erosions if: 1

• Treatment failure occurs
• MRSA is suspected
• Recurrent infections are present
• Antimicrobial therapy should be active against both S. aureus and streptococci 1

Pediatric Considerations

• Oral antibiotic dosing must be adjusted by weight for children 1
• Tetracyclines (doxycycline, minocycline) should not be used in children under 8 years of age 1
• Mupirocin demonstrated 78% efficacy in pediatric patients aged 2 months to 15 years versus 36% for placebo 3

Treatment Monitoring and Follow-up

• Re-evaluate if no improvement occurs after 48-72 hours of therapy 1, 2
• Topical treatment duration: 5-7 days 1, 2
• Oral antibiotic duration: 7 days 2
• Lesions should be kept covered with clean, dry bandages and good personal hygiene maintained to prevent spread 1, 2

Risk Factors for MRSA

Empiric therapy for community-acquired MRSA should be considered in patients with: 5

• Residence in long-stay care facilities
• Hospitalization within the preceding 30 days
• Recent antibiotic therapy (especially beta-lactams, cephalosporins, carbapenems, or quinolones)
• Failure to respond to first-line therapy