What is the treatment for otitis externa?

Treatment of Otitis Externa

The first-line treatment for otitis externa is topical antimicrobial therapy with a fluoroquinolone preparation containing corticosteroids, such as ciprofloxacin 0.3%/dexamethasone 0.1%, administered as 3-4 drops twice daily for 7 days. 1

Diagnosis Confirmation

Before initiating treatment, confirm the diagnosis of acute otitis externa (AOE) by identifying:

• Rapid onset (within 48 hours) in the past 3 weeks
• Symptoms: otalgia (ear pain), itching, fullness, with or without hearing loss
• Signs: tenderness of tragus/pinna, ear canal edema, and erythema 1

Treatment Algorithm

Step 1: Assess for Modifying Factors

• Check for non-intact tympanic membrane or tympanostomy tubes
• Identify if patient has diabetes or is immunocompromised
• Determine if patient has received prior radiotherapy 2

Step 2: Pain Management

• Assess pain severity and treat accordingly:
  • Mild to moderate pain: acetaminophen or NSAIDs
  • Severe pain: may require short-term opioids (48-72 hours) 2, 1

Step 3: Ear Canal Preparation

• If ear canal is obstructed with debris:
  • Perform gentle cleaning using suction, dry mop technique, or gentle lavage with body-temperature water/saline
  • Place a wick (preferably compressed cellulose) in severely obstructed ear canals to enhance drug delivery
  • Remove wick once ear canal edema subsides (typically within 24-72 hours) 1

Step 4: Topical Antimicrobial Therapy

• For intact tympanic membrane:

  • Fluoroquinolone with corticosteroid (ciprofloxacin 0.3%/dexamethasone 0.1%) - 3-4 drops twice daily for 7 days 1, 3
  • Alternative: ofloxacin 0.3% solution - 10 drops (for patients ≥13 years) or 5 drops (for patients 6 months to 13 years) once daily for 7 days 4, 5

• For non-intact tympanic membrane or tympanostomy tubes:

  • Use only non-ototoxic preparations (fluoroquinolones)
  • Avoid aminoglycoside-containing products (neomycin/polymyxin B) due to potential ototoxicity 2, 1, 6

Step 5: Administration Technique

• Warm the solution by holding the container in hands for at least 1 minute
• Have patient lie with affected ear upward
• Instill prescribed drops into ear canal
• Maintain position for 3-5 minutes
• Use gentle to-and-fro movement of pinna or tragal pumping to help drops penetrate 1, 3

Step 6: Systemic Antibiotics

• Do not prescribe systemic antibiotics for uncomplicated otitis externa 2, 1
• Only use systemic antibiotics if:
  • Infection extends beyond the ear canal
  • Patient has diabetes or is immunocompromised
  • Patient has malignant otitis externa 2, 1
• If systemic antibiotics are needed, select those active against both Pseudomonas aeruginosa and Staphylococcus aureus 2

Special Considerations

Fungal Otitis Externa (Otomycosis)

• Suspect if patient fails to respond to initial topical antibiotic therapy
• Appears as white debris with hyphae (Candida) or moist white plug with black debris (Aspergillus niger)
• Treatment: debridement plus topical antifungal therapy
• Avoid topical antibiotics as they may promote fungal overgrowth 2

Treatment Failure

• If no improvement after 48-72 hours:
  • Reassess diagnosis
  • Check for proper medication administration
  • Consider fungal infection
  • Consider alternative topical therapy 1
  • Assess adherence to therapy 2

Evidence Quality and Efficacy

Topical fluoroquinolones have demonstrated high efficacy in clinical trials:

• Ofloxacin 0.3% solution once daily for 7 days achieved 91% clinical cure rate 5
• Once-daily ofloxacin was as effective as neomycin/polymyxin B/hydrocortisone four times daily (93.8% vs 94.7% cure rates) 7
• Ciprofloxacin otic solution achieved 70% clinical cure rate at 7 days 3

Fluoroquinolones offer several advantages over neomycin/polymyxin B combinations:

• No risk of ototoxicity when tympanic membrane is not intact 6, 8
• Less frequent dosing improves patient adherence 5, 7, 8
• Equally effective against common pathogens 7, 9

Prevention of Recurrence

• Keep ears dry
• Use ear protection (earplug or cotton with petroleum jelly) when showering or washing hair
• Consider acidifying ear drops after swimming if recurrent episodes occur
• Avoid inserting foreign objects into the ear canal 1