What is the recommended treatment for an adult with otitis externa?

Treatment of Otitis Externa in Adults

The recommended first-line treatment for uncomplicated otitis externa in adults is topical fluoroquinolone ear drops, such as ofloxacin 0.3% (10 drops once daily for 7 days) or ciprofloxacin 0.2% (twice daily for 7 days). 1, 2, 3

Diagnostic Considerations

• Distinguish diffuse acute otitis externa from other causes of otalgia, otorrhea, and ear canal inflammation 4
• Assess for modifying factors that may alter management:
  • Non-intact tympanic membrane
  • Tympanostomy tube
  • Diabetes
  • Immunocompromised state
  • Prior radiotherapy 4, 1

Treatment Algorithm

1. Initial Topical Therapy

• First-line options:

  • Ofloxacin 0.3% otic solution: 10 drops once daily for 7 days (adults) 1, 2, 5
  • Ciprofloxacin 0.2% otic solution: twice daily for 7 days 1, 3
  • Ciprofloxacin 0.3%/dexamethasone 0.1% combination: 3-4 drops twice daily for 7 days 6, 7

• For non-intact tympanic membrane:

  • Use non-ototoxic preparations (avoid aminoglycosides) 4, 1
  • Ofloxacin is safe for perforated tympanic membranes 2

2. Pain Management

• Assess pain severity and provide appropriate analgesia 4
• Acetaminophen or NSAIDs for immediate pain relief 1
• Pain typically improves within 48 hours of starting treatment 1

3. Ear Canal Preparation

• Perform aural toilet to remove debris and enhance medication delivery 4
• Consider ear wick placement for severe canal edema 1
• Instruct patient on proper administration:
  • Warm drops by holding bottle in hand for 1-2 minutes
  • Lie with affected ear upward
  • Maintain position for 5 minutes after instillation 1, 2

4. When to Consider Systemic Antibiotics

• Do not use systemic antibiotics as initial therapy for uncomplicated cases 4, 1
• Consider systemic antibiotics only if:
  • Infection extends beyond the ear canal
  • Cellulitis of the pinna with systemic signs
  • High fever
  • Severe canal edema preventing topical therapy 4, 1

Monitoring and Follow-up

• Reassess within 48-72 hours if no improvement 4
• Clinical cure rates with recommended treatments range from 70-91% 3, 5
• Complete the full 7-day course even if symptoms improve earlier 1

Special Considerations

• Diabetic patients: Higher risk for severe infections, fungal otitis externa, and potential progression to malignant (necrotizing) otitis externa 1
• Fungal otitis externa: Consider topical azole antifungals (clotrimazole or miconazole) 1
• Post-radiation patients: Require delicate debridement and are at higher risk of poor healing 1

Prevention Strategies

• Avoid excessive moisture in ear canal 1, 8
• Dry ears thoroughly after water exposure 1
• Consider prophylactic acidifying solutions (2% acetic acid) after swimming 1, 8
• Avoid inserting cotton-tipped swabs into the ear canal 1

Common Pitfalls to Avoid

1. Using neomycin-containing products as first-line therapy (can cause sensitization in 5-15% of patients) 1
2. Prescribing systemic antibiotics for uncomplicated cases (lower cure rates, more side effects, contributes to antibiotic resistance) 4, 1, 9
3. Inadequate pain management 4
4. Premature discontinuation of treatment 1
5. Using ear candles (no proven benefit, potential harm) 1

The evidence strongly supports topical therapy as the mainstay of treatment for otitis externa, with systemic antibiotics reserved for specific circumstances. Fluoroquinolone preparations have demonstrated excellent efficacy and safety profiles, with once-daily ofloxacin offering the advantage of convenient dosing and high adherence rates.