What is the treatment for non-bullous impetigo?

Treatment of Non-Bullous Impetigo

For non-bullous impetigo with limited lesions, topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment, but switch to oral antibiotics (dicloxacillin 250 mg four times daily or cephalexin 250-500 mg four times daily for adults) if lesions are extensive, involve multiple sites, or fail to respond after 3-5 days. 1, 2

Initial Assessment and Treatment Selection

When to Use Topical Therapy

• Topical mupirocin 2% ointment applied three times daily for 5-7 days is the preferred first-line treatment for localized impetigo 1, 2, 3
• Retapamulin applied twice daily for 5 days is an alternative topical option 1
• Topical therapy is preferred for limited disease due to fewer systemic side effects 2
• Do not use bacitracin or neomycin—they are considerably less effective and should not be used for impetigo treatment 4

When to Switch to Oral Antibiotics

You must use oral antibiotics in these situations:

• Extensive disease or numerous lesions 1, 4
• Lesions on the face, eyelid, or mouth 4
• No response to topical therapy after 3-5 days 4, 2
• Outbreaks affecting multiple people (to decrease transmission) 1
• Systemic symptoms present 4
• When topical therapy is impractical 2

Oral Antibiotic Regimens

For Presumed Methicillin-Susceptible S. aureus (MSSA)

Most S. aureus isolates from impetigo are methicillin-susceptible, making these your first-line oral options: 1

• Dicloxacillin 250 mg four times daily for adults (7-10 days) 1, 4, 2
• Cephalexin 250-500 mg four times daily for adults (7-10 days) 1, 4, 2

For Suspected or Confirmed MRSA

If MRSA is suspected or confirmed, use one of these agents: 1

• Clindamycin 300-450 mg three times daily for adults 1, 4, 2
• Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily for adults 1, 4
• Doxycycline (alternative option) 1

If Cultures Yield Streptococci Alone

• Oral penicillin is the recommended agent when only streptococci are isolated 1
• Critical pitfall: Penicillin alone is NOT effective for impetigo when S. aureus is present, as it lacks adequate staphylococcal coverage 4, 2

Culture Guidance

Gram stain and culture of pus or exudates are recommended to identify whether S. aureus and/or β-hemolytic Streptococcus is the cause, but treatment without these studies is reasonable in typical cases 1

When Cultures Are Strongly Recommended:

• Treatment failure 4, 2
• MRSA is suspected 4, 2
• Recurrent infections 4, 2

Duration of Therapy

• Topical treatment: 5-7 days 1, 4, 2
• Oral antibiotics: 7-10 days 1, 4, 2

Special Populations

Pediatric Patients

• Dicloxacillin: 12 mg/kg/day in 4 divided doses 2
• Avoid tetracyclines (doxycycline, minocycline) in children under 8 years 4, 2
• Topical mupirocin has demonstrated 78% clinical efficacy in pediatric patients aged 2 months to 15 years 3

Pregnant Patients

• Cephalexin is generally considered safe for pregnant patients 4, 2
• Avoid tetracyclines in pregnant women 4, 2

Penicillin-Allergic Patients

• Clindamycin is the preferred alternative for penicillin-allergic patients 4

Prevention of Spread

• Keep lesions covered with clean, dry bandages 4, 2
• Maintain good personal hygiene with regular handwashing 4
• Avoid sharing personal items that contact the skin 4

Monitoring and Follow-Up

• Re-evaluate if no improvement after 48-72 hours of therapy 2
• Consider alternative diagnosis if presentation is atypical or not responding to appropriate therapy 2

Special Circumstances: Poststreptococcal Glomerulonephritis Outbreaks

Systemic antimicrobials should be used for infections during outbreaks of poststreptococcal glomerulonephritis to help eliminate nephritogenic strains of Streptococcus pyogenes from the community 1