What is the treatment for cutaneous anthrax?

Treatment for Cutaneous Anthrax

For cutaneous anthrax, first-line therapy is ciprofloxacin 500 mg orally twice daily or doxycycline 100 mg orally twice daily for 60 days. 1

Treatment Algorithm

Initial Assessment and Classification

1. Uncomplicated cutaneous anthrax:

   • Painless papule that progresses to vesicular stage, then develops into a black eschar
   • Minimal surrounding edema
   • No systemic symptoms

2. Complicated cutaneous anthrax (requires more aggressive treatment):

   • Signs of systemic involvement (fever, toxemia)
   • Extensive edema
   • Lesions on the head or neck
   • Immunocompromised status

Treatment Regimens

For Uncomplicated Cutaneous Anthrax:

• First-line oral therapy (choose one):
  • Ciprofloxacin 500 mg twice daily for 60 days 1, 2
  • Doxycycline 100 mg twice daily for 60 days 1, 3

For Complicated Cutaneous Anthrax:

• Intravenous therapy with multidrug regimen 1:
  • Ciprofloxacin 400 mg IV every 12 hours OR
  • Doxycycline 100 mg IV every 12 hours
  • PLUS one or two additional antimicrobials with in vitro activity (rifampin, vancomycin, imipenem, chloramphenicol, clindamycin, or clarithromycin)
  • Switch to oral therapy when clinically appropriate
  • Continue for total of 60 days (IV and oral combined)

Special Populations

Children:

• Ciprofloxacin: 10-15 mg/kg every 12 hours (not to exceed 1 g/day) 1, 2
• Doxycycline 1, 3:

  • 8 years and >45 kg: 100 mg every 12 hours

  • 8 years and ≤45 kg: 2.2 mg/kg every 12 hours

  • ≤8 years: 2.2 mg/kg every 12 hours

Pregnant Women:

• Same regimens as for non-pregnant adults 1
• The high mortality risk from infection outweighs the risks posed by the antimicrobial agents
• Doxycycline might be used for short periods (7-14 days) before six months of gestation if necessary 1

Important Clinical Considerations

1. Antimicrobial treatment effects:

   • Lesions may become culture-negative within 24 hours of starting antibiotics
   • Progression to eschar formation will still occur despite treatment 1

2. Duration of therapy:

   • While typical cutaneous anthrax has traditionally been treated for 7-10 days, the current recommendation is 60 days due to the risk of simultaneous aerosol exposure and potential for reactivation of latent infection 1

3. Avoid certain antibiotics:

   • Cephalosporins and trimethoprim-sulfamethoxazole should not be used 1
   • Penicillin G and ampicillin alone should not be used due to concerns about beta-lactamases in B. anthracis 1

4. Adjunctive therapy:

   • Corticosteroids may be considered for severe edema, but evidence for benefit is limited 1, 4

5. Surgical intervention:

   • Generally not recommended for uncomplicated cases 5
   • Most cutaneous anthrax lesions heal without scar formation with appropriate antibiotic therapy 5

Monitoring and Follow-up

• Monitor for resolution of edema and fever
• Watch for development of systemic symptoms that would indicate progression to more severe disease
• Complete the full 60-day course of antibiotics even if symptoms resolve quickly 1

By following this treatment algorithm, the mortality and morbidity associated with cutaneous anthrax can be significantly reduced, with most patients experiencing complete recovery.