What oral antibiotics can be prescribed for an infected pinna?

Oral Antibiotics for Infected Pinna

For an infected pinna, first-line oral antibiotic treatment should be amoxicillin-clavulanate 875/125 mg twice daily for 10-14 days. 1

First-Line Options

• Amoxicillin-clavulanate: 875/125 mg twice daily for 10-14 days
  • Provides broad-spectrum coverage including anaerobes
  • Effective for most moderate skin and soft tissue infections

Alternative Options (for penicillin allergies or based on suspected pathogens)

1. Clindamycin: 300-600 mg every 8 hours 2

   • Effective against streptococcal and staphylococcal infections
   • Caution: High resistance rates in some areas
   • Consider D-test before using for suspected MRSA

2. Doxycycline: 100 mg every 12 hours 2, 3

   • Initial dose: 200 mg on first day (100 mg every 12 hours)
   • Maintenance: 100 mg every 12 hours
   • Take with food or milk to reduce gastrointestinal irritation

3. Trimethoprim-sulfamethoxazole (TMP-SMX): 160/800 mg every 12 hours 2

   • Particularly effective for community-acquired MRSA
   • Limited activity against β-hemolytic streptococci

4. Cephalexin: 500 mg every 6-8 hours 4, 5

   • Effective for streptococcal and methicillin-sensitive S. aureus
   • Contraindicated in patients with immediate penicillin hypersensitivity
   • 90% cure rates for skin and soft tissue infections

Treatment Considerations

Pathogen Considerations

• Most auricular infections involve S. aureus or Streptococcus species
• Consider MRSA coverage if:
  • Previous MRSA infection
  • High local prevalence
  • Recent hospitalization
  • Recent antibiotic use 1

Severity Assessment

• Mild infection: Localized erythema, minimal pain
• Moderate infection: More extensive inflammation, moderate pain
• Severe infection: Systemic symptoms, extensive involvement
  • Consider IV antibiotics and hospitalization for severe infections 1

Duration of Treatment

• 10-14 days for moderate infections
• 7-10 days for mild infections
• 14-21 days for severe infections 1

Adjunctive Measures

• Incision and drainage if abscess is present
• Warm compresses to promote drainage
• Proper wound care essential for treatment success

Special Considerations

• If no improvement after 48-72 hours:
  • Reassess diagnosis
  • Consider culture and sensitivity testing
  • Evaluate for deeper infection or abscess formation
  • Consider switching antibiotics

Potential Pitfalls

1. Intracellular persistence: S. aureus can be internalized by keratinocytes, evading most antibiotics except rifampicin 6
2. Biofilm formation: May lead to treatment failure and recurrence
3. Inadequate drainage: Antibiotics alone may be insufficient if abscess is present
4. Antibiotic resistance: Local resistance patterns should guide therapy

Follow-up

• Clinical improvement should be evident within 48-72 hours
• Complete the full course of antibiotics even if symptoms resolve quickly
• Consider surgical consultation if there is evidence of deep tissue involvement, necrosis, or poor response to antibiotics