What is the recommended treatment for impetigo?

Treatment of Impetigo

Topical mupirocin 2% ointment applied three times daily is the first-line treatment for limited impetigo, while oral antibiotics such as dicloxacillin or cephalexin should be used for extensive disease, treatment failure after 3-5 days, or systemic symptoms. 1

Initial Treatment Selection Based on Disease Extent

For limited, localized lesions:

• Start with topical mupirocin 2% ointment applied three times daily, which is FDA-approved and the most effective topical agent for impetigo caused by S. aureus and S. pyogenes 1, 2
• Retapamulin ointment 1% applied twice daily for 5 days is an alternative topical option for patients 9 months or older 1, 3
• Avoid bacitracin and neomycin as they are considerably less effective 1
• Continue topical therapy for 5-7 days 1

Switch to oral antibiotics if:

• Impetigo is extensive at presentation 1
• No response to topical therapy after 3-5 days 1
• Systemic symptoms are present 1
• Lesions involve the face, eyelid, or mouth 1
• Need to rapidly limit spread to others 1

Oral Antibiotic Selection

For presumed methicillin-susceptible S. aureus (MSSA):

• Dicloxacillin 250 mg four times daily for adults (12 mg/kg/day in 4 divided doses for children) 4
• Cephalexin 250-500 mg four times daily for adults (25 mg/kg/day in 4 divided doses for children) 4
• Amoxicillin-clavulanate 875/125 mg twice daily for adults (25 mg/kg/day of amoxicillin component in 2 divided doses for children) 4
• Duration: 5-10 days 4

For suspected or confirmed MRSA:

• Clindamycin 300-450 mg three times daily for adults (10-20 mg/kg/day in 3 divided doses for children) 1, 4
• Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily for adults (8-12 mg/kg/day based on trimethoprim component in 2 divided doses for children) 1, 4
• Doxycycline 100 mg twice daily for adults (avoid in children under 8 years) 4

Critical caveat: Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 1, 4

Management of Treatment Failure

If impetigo is refractory to mupirocin:

• Initiate oral antibiotics (dicloxacillin, cephalexin, clindamycin, or amoxicillin-clavulanate) 4
• Consider mupirocin resistance, especially in areas with high MRSA prevalence 4
• Obtain cultures from lesions to guide therapy 1, 4
• Re-evaluate if no improvement after 48-72 hours of oral therapy 4

For treatment failure with oral antibiotics:

• Consider hospitalization with IV antibiotics such as vancomycin for MRSA 4
• Linezolid is an option for MRSA resistant to clindamycin: 30 mg/kg/day in 3 doses for children under 12 years, 20 mg/kg/day in 2 doses for children 12 years and older 4

Special Population Considerations

Pregnant patients:

• Cephalexin is generally considered safe 4
• Avoid tetracyclines 4

Children under 8 years:

• Avoid doxycycline and other tetracyclines 1, 4

Penicillin-allergic patients:

• Clindamycin is the preferred alternative 1

Prevention of Spread

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

Recurrent Impetigo

• Consider decolonization strategies for S. aureus carriers 4
• Obtain cultures to identify resistant organisms 1