First-Line Treatment for Impetigo
Topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for localized, uncomplicated impetigo. 1, 2
Understanding Impetigo
Impetigo is a common superficial bacterial skin infection that presents in two forms:
- Nonbullous impetigo (70% of cases): Characterized by honey-colored crusts, caused by Staphylococcus aureus and/or Streptococcus pyogenes
- Bullous impetigo (30% of cases): Characterized by flaccid bullae, exclusively caused by S. aureus
The infection typically affects exposed areas of the body, particularly the face and extremities, and is most common in children aged 2-5 years 3.
Treatment Algorithm
1. Localized, Limited Lesions
- First-line: Topical mupirocin 2% ointment applied three times daily for 5-7 days 1, 2
- Alternative topical option: Retapamulin 2
2. Extensive Disease or Multiple Lesions
- First-line oral therapy: Oral penicillinase-resistant penicillin or first-generation cephalosporin 2
- Cephalexin: 500 mg orally 4 times daily for 5-7 days (adults)
- Dicloxacillin: 500 mg orally 4 times daily for 5-7 days (adults)
3. For Penicillin-Allergic Patients
4. When MRSA is Suspected
- First-line options:
Evidence-Based Rationale
Topical mupirocin has demonstrated equal efficacy to oral antibiotics in the treatment of localized impetigo 5. The Infectious Diseases Society of America (IDSA) guidelines support this approach, noting that topical mupirocin is as effective as oral antimicrobials for impetigo 2.
Clinical studies have shown that mupirocin treatment produces similar clinical results to oral erythromycin and is superior in eradicating S. aureus, including antibiotic-resistant strains 5. Mupirocin has excellent in vitro and in vivo activity against gram-positive staphylococci and streptococci, the predominant pathogens in impetigo 6.
Important Considerations
- Culture considerations: Cultures of vesicle fluid, pus, or erosions may be useful in cases of treatment failure or unusual presentations 2
- Systemic therapy indications: Systemic therapy is preferred for patients with numerous lesions or in outbreaks affecting several people to help decrease transmission 2
- Treatment duration: Complete the full 5-7 day course even if lesions appear to be improving earlier 4
- Resistance concerns: Be aware of potential resistance to mupirocin in areas with high usage 3
Pediatric Considerations
- Topical mupirocin is safe and effective for children 2
- For systemic therapy in children, dosing should be adjusted by weight
- Tetracyclines (doxycycline, minocycline) should not be used in children under 8 years of age 2
Prevention Measures
- Good hygiene practices
- Avoid sharing personal items
- Proper wound care
- Prompt identification and treatment of infected individuals 2
Mupirocin offers several advantages over systemic antibiotics, including fewer adverse effects, lower cost, easier administration, and reduced likelihood of inducing antibiotic resistance 6, making it an excellent first-line choice for uncomplicated impetigo.