What is the empirical antibiotic therapy for preauricular collections?

Empirical Antibiotic Therapy for Preauricular Collections

For preauricular collections (sinuses/cysts), the empirical antibiotic therapy should be directed at common skin pathogens, with cloxacillin or amoxicillin-clavulanate as first-line choices. 1

First-Line Empirical Therapy Options

• Oral therapy for mild to moderate infections:

  • Cloxacillin (first choice) 1
  • Amoxicillin-clavulanate (first choice) 1
  • Cefalexin (first choice) 1

• For patients with penicillin allergy:

  • Clindamycin (provides good coverage against Staphylococcus aureus and streptococci) 1

Rationale for Antibiotic Selection

• Preauricular collections are primarily caused by skin pathogens, with Staphylococcus aureus and beta-hemolytic streptococci being the most common causative organisms 2, 3
• The Infectious Diseases Society of America (IDSA) guidelines recommend anti-staphylococcal coverage for skin and soft tissue infections 1
• WHO's Essential Medicines recommendations support using cloxacillin, amoxicillin-clavulanate, or cefalexin as first-line agents for mild skin and soft tissue infections 1

Management Algorithm for Infected Preauricular Collections

1. Initial assessment:

   • Determine severity of infection (mild, moderate, severe)
   • Assess for systemic symptoms (fever, chills) 1
   • Check for extension beyond preauricular area 3, 4

2. For mild to moderate infections (outpatient management):

   • Oral antibiotics (see first-line options above)
   • Duration: 7-10 days 3, 5
   • Consider needle aspiration rather than incision and drainage 5

3. For severe infections or treatment failure:

   • Consider parenteral therapy:
     • Cefazolin (for MSSA coverage) 1, 2
     • Vancomycin (if MRSA suspected) 1, 6
   • Consider hospitalization if:
     • Extensive cellulitis
     • Systemic symptoms
     • Immunocompromised patient 1

4. For recurrent or persistent infections:

   • Surgical excision of the preauricular sinus/cyst is the definitive treatment 3, 4
   • Control infection with antibiotics before definitive surgery 3

Special Considerations

• MRSA coverage: If MRSA is suspected based on local prevalence or patient risk factors, consider:

  • Trimethoprim-sulfamethoxazole 1
  • Daptomycin (for severe infections requiring IV therapy) 6
  • Linezolid (for severe infections) 1

• Avoid incision and drainage if possible: Studies suggest that incision and drainage of infected preauricular cysts is associated with higher recurrence rates (18.5%) compared to needle aspiration or antibiotic treatment alone (3.3%) 5

• Pediatric considerations: The same antibiotic choices apply to children, with appropriate dose adjustments based on weight 3, 5

Common Pitfalls to Avoid

• Failure to recognize the underlying preauricular sinus: This can lead to inadequate treatment and unnecessary surgical procedures 4
• Premature surgical excision: Complete excision should be performed after the acute infection has resolved 3, 4
• Inadequate antibiotic duration: Ensure a full course of antibiotics is completed to prevent recurrence 3
• Overuse of broad-spectrum antibiotics: Reserve broader coverage for severe infections or treatment failures 1

Remember that while antibiotics are essential for treating the acute infection, definitive treatment of recurrent preauricular sinus infections ultimately requires complete surgical excision of the sinus tract 3, 4.