Honey-Colored Crusted Lesions: Impetigo
Diagnosis
The honey-colored crusted lesions are pathognomonic for nonbullous impetigo, the most common bacterial skin infection in children, caused by Staphylococcus aureus, Streptococcus pyogenes, or both. 1
Clinical Features to Confirm Diagnosis:
- Erythematous papules that rapidly evolve into vesicles, then pustules, and finally form characteristic thick honey-colored crusts 1
- Lesions typically occur on exposed areas, most frequently the face and extremities 1
- Pustules enlarge and break down over 4-6 days before forming crusts 1
- Regional lymphadenitis may be present, but systemic symptoms are usually absent 1
When to Obtain Cultures:
- Treatment failure after 48-72 hours of appropriate therapy 1, 2
- Suspected MRSA infection 1, 2
- Recurrent infections 1, 2
- Culture vesicle fluid, pus, or erosions to guide antibiotic selection 1
Treatment Algorithm
For Localized Disease (Few Lesions, Single Body Area):
Topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment. 1, 2
- Topical antibiotics are superior to placebo and equal or superior to oral antibiotics for localized disease (RR 2.24,95% CI 1.61-3.13) 1
- Alternative: Retapamulin 1% ointment applied twice daily for 5 days 2, 3
- Keep lesions covered with clean, dry bandages to prevent spread 2, 3
For Extensive Disease (Multiple Sites, Numerous Lesions, or Topical Therapy Impractical):
Use oral antibiotics for 7-10 days. 2
First-Line Oral Options (Presumed MSSA):
- Dicloxacillin 250 mg four times daily for adults (12 mg/kg/day in 4 divided doses for children) 2, 3
- Cephalexin 250-500 mg four times daily for adults 2, 3
For Suspected or Confirmed MRSA:
- Clindamycin 300-450 mg three times daily for adults 2, 3
- Trimethoprim-sulfamethoxazole (TMP-SMX) 1, 2
- Doxycycline (avoid in children <8 years and pregnant women) 2, 3
Critical Pitfalls to Avoid
- Never use penicillin alone—it lacks adequate coverage against S. aureus, which is now the predominant pathogen 3, 4
- Do not use tetracyclines (doxycycline, minocycline) in children under 8 years of age 1, 2
- Re-evaluate if no improvement after 48-72 hours and consider obtaining cultures to guide therapy 1, 2
- Topical disinfectants are inferior to antibiotics and should not be used 1, 4
Special Considerations
Rising Antibiotic Resistance:
- Methicillin-resistant S. aureus (MRSA), macrolide-resistant streptococcus, and mupirocin-resistant streptococcus are increasingly documented 4
- Empiric MRSA coverage should be considered in areas with high community prevalence or in treatment failures 1, 2
During Outbreaks:
- Systemic antimicrobials should be used during outbreaks of poststreptococcal glomerulonephritis to eliminate nephritogenic strains of Streptococcus pyogenes 1