How should impetigo on the chin be treated?

Treatment of Impetigo on the Chin

Start with topical mupirocin 2% ointment applied three times daily for 5-7 days as first-line treatment for localized impetigo on the chin. 1, 2

First-Line Topical Therapy

• Mupirocin 2% ointment is the gold standard treatment, with clinical efficacy rates of 71-93% in controlled trials and FDA approval specifically for impetigo caused by S. aureus and S. pyogenes. 1, 2
• Apply three times daily for 5-7 days to the affected area on the chin. 1, 3
• Retapamulin 1% ointment twice daily for 5 days is an effective alternative if mupirocin is unavailable. 1, 3
• Avoid bacitracin and neomycin—they are considerably less effective and should not be used. 1, 4

When to Escalate to Oral Antibiotics

Switch to systemic therapy if any of the following occur:

• No improvement after 48-72 hours (or 3-5 days) of topical therapy 1, 4
• Extensive disease involving multiple sites 4, 3
• Systemic symptoms present (fever, malaise, lymphadenopathy) 1, 4
• Need to limit spread to others, such as during outbreaks 4
• Lesions on face/mouth where topical therapy is impractical 4

Oral Antibiotic Selection

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

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

For Suspected or Confirmed MRSA:

• Clindamycin 300-450 mg three times daily for adults 1, 4
• Trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily 1, 4
• Doxycycline (contraindicated in children under 8 years) 1, 3

Critical Pitfalls to Avoid

• Never use penicillin alone—it lacks adequate coverage against S. aureus 1, 4
• Do not use rifampin as monotherapy or adjunctive therapy for skin infections 1
• Avoid tetracyclines (doxycycline, minocycline) in children under 8 years 1, 3
• Do not use topical clindamycin cream (designed for acne, not impetigo) 4
• Avoid cephalosporins if patient has type 1 hypersensitivity (anaphylaxis/hives) to β-lactams 4

Infection Control and Prevention

• Keep lesions covered with clean, dry bandages 4
• Maintain good personal hygiene with regular handwashing 4
• Avoid sharing personal items that contact the skin (towels, equipment) 5, 4
• For athletes, exclude from participation until 24 hours after initiation of effective antimicrobial therapy 4

When to Obtain Cultures

Cultures are not routinely necessary for typical limited impetigo, but obtain them if: 4, 3

• Treatment failure occurs
• MRSA is suspected
• Recurrent infections develop
• Patient is immunocompromised

Special Populations

• Pediatric patients: Use mupirocin 2% topical ointment as first-line; avoid tetracyclines under age 8 1, 4
• Pregnant patients: Cephalexin is a safe alternative 4
• Penicillin-allergic patients: Clindamycin is the preferred alternative 4
• Immunocompromised patients: Lower threshold for oral antibiotics; monitor closely for treatment failure or deeper infection 4

Treatment During Outbreaks

• Use systemic antimicrobials to help eliminate nephritogenic strains of S. pyogenes from the community 5, 4
• Consider decolonization strategies using topical nasal mupirocin therapy for S. aureus carriers 4
• Involve public health authorities for outbreak management 5