What are the broad-spectrum antibiotic options for treating skin abscesses?

Broad-Spectrum Antibiotic Options for Skin Abscesses

For skin abscesses requiring antibiotic therapy, trimethoprim-sulfamethoxazole (TMP-SMX) or clindamycin are the preferred first-line options due to their efficacy against MRSA and other common pathogens. 1

When Antibiotics Are Indicated for Skin Abscesses

While incision and drainage remains the primary treatment for most simple abscesses, antibiotics are recommended in the following situations:

• Systemic signs of infection (fever, tachycardia) 1
• Immunocompromised patients 1
• Incomplete source control after drainage 1
• Significant surrounding cellulitis 1, 2
• Abscess size >5 cm 2, 3
• Multiple sites of infection 2
• History of MRSA infection 3

First-Line Oral Options

• Trimethoprim-sulfamethoxazole (TMP-SMX): 160-800 mg twice daily for adults 1, 2

  • Good activity against aerobes including MRSA
  • Poor activity against anaerobes
  • Clinical trial evidence shows 81.7% cure rate for abscesses 2

• Clindamycin: 300-450 mg three times daily for adults 1

  • Good activity against staphylococci, streptococci, and anaerobes
  • Clinical trial evidence shows 83.1% cure rate for abscesses 2
  • Higher rate of adverse effects (21.9%) compared to TMP-SMX (11.1%) 2

Alternative Oral Options

• Doxycycline: 100 mg twice daily 1

  • Good activity against MRSA and some anaerobes
  • Some streptococci may be resistant
  • Not recommended for children under 8 years 1

• Linezolid: 600 mg twice daily 1

  • Effective against MRSA and other gram-positive pathogens
  • Expensive option with more side effects
  • Reserved for severe infections or when other options fail 1

• Cephalexin: 500 mg four times daily 1

  • Effective against methicillin-susceptible S. aureus (MSSA)
  • Not effective against MRSA
  • May be combined with TMP-SMX for broader coverage 1

Parenteral Options for Severe Infections

• Vancomycin: 15-20 mg/kg every 8-12 hours IV 1

  • Drug of choice for severe MRSA infections requiring IV therapy
  • Requires therapeutic drug monitoring

• Daptomycin: 4 mg/kg every 24 hours IV 1

  • Bactericidal against MRSA
  • Monitor for myopathy

• Ceftaroline: 600 mg twice daily IV 1

  • Active against MRSA and many gram-negative pathogens
  • Newer cephalosporin with anti-MRSA activity

• Ampicillin-sulbactam: 1.5-3.0 g every 6 hours IV 1

  • Good for polymicrobial infections including anaerobes
  • Not effective against MRSA

Special Considerations

Complex Abscesses (Perianal, Perirectal, IV Drug Use Sites)

For complex abscesses, broader coverage is often needed:

• Amoxicillin-clavulanate: 875/125 mg twice daily 1

  • Covers many gram-positive and gram-negative organisms
  • Not effective against MRSA

• Moxifloxacin: 400 mg daily 1

  • Monotherapy with good anaerobic coverage
  • Not first-line for MRSA

Duration of Therapy

• 5-10 days of antibiotics is typically sufficient 1
• Treatment should be extended if infection has not improved within 5 days 1

Pediatric Considerations

• Clindamycin: 10-13 mg/kg/dose every 8 hours IV or 10-20 mg/kg/day in 3 divided doses orally 1
• TMP-SMX: 8-12 mg/kg/day (based on trimethoprim component) in 2 divided doses 1
• Tetracyclines should not be used in children under 8 years of age 1

Microbiology and Resistance Considerations

• S. aureus (including MRSA) is the predominant pathogen in skin abscesses 2, 3
• Consider local resistance patterns when selecting empiric therapy 1
• Obtain cultures in recurrent cases to guide therapy 1

Prevention of Recurrence

For patients with recurrent abscesses, consider:

• 5-day decolonization regimen with intranasal mupirocin
• Daily chlorhexidine washes
• Daily decontamination of personal items (towels, sheets, clothes) 1