What is the treatment for otitis externa?

Treatment of Otitis Externa

The first-line treatment for acute otitis externa (AOE) is topical antimicrobial therapy, which delivers medication concentrations 100-1000 times higher than systemic therapy and effectively targets common pathogens like Pseudomonas aeruginosa and Staphylococcus aureus. 1, 2

Diagnosis

• AOE is defined as diffuse inflammation of the external ear canal with rapid onset (generally within 48 hours) in the past 3 weeks, presenting with symptoms such as ear pain, itching, or fullness, with or without hearing loss 3
• Nearly 98% of AOE cases in North America are bacterial, with Pseudomonas aeruginosa (20-60%) and Staphylococcus aureus (10-70%) being the most common pathogens 2

Initial Management

• Perform aural toilet to remove debris and enhance medication delivery before administering topical therapy, using gentle suction, dry mopping, or irrigation 1, 4
• Place a wick in the ear canal if edema prevents drop entry or if most of the tympanic membrane cannot be visualized 1
• Prescribe topical antimicrobial preparations effective against common pathogens, such as those containing aminoglycosides, polymyxin B, quinolones, or low-pH antiseptics 1, 2
• Meta-analyses show no significant differences in clinical outcomes based on class of drug (antibiotic vs antiseptic), quinolone versus non-quinolone preparations, or monotherapy versus combination drugs 2, 5

Pain Management

• Assess pain severity and prescribe appropriate analgesics, as pain from AOE can be intense due to the highly sensitive periosteum of the underlying bone 3, 1
• For mild to moderate pain, acetaminophen or nonsteroidal anti-inflammatory drugs are typically effective 3
• For severe pain, consider short-term opioid-containing analgesics for the initial 48-72 hour period 1, 3
• Pain typically improves within 48-72 hours of starting appropriate treatment 1, 4

Special Considerations

• For non-intact tympanic membrane (perforation or tympanostomy tubes), use only non-ototoxic preparations such as quinolones (ciprofloxacin or ofloxacin) 1, 4
• Adding a topical steroid to antimicrobial drops helps reduce inflammation and hasten pain relief 1, 5
• For suspected fungal otitis externa, use topical antifungal therapy and debridement, avoiding antibacterial drops that may promote fungal overgrowth 4, 3
• Patients with diabetes or immunocompromised states require special consideration as they are susceptible to otomycosis and necrotizing otitis externa 2, 4

When to Use Systemic Antibiotics

• Systemic antibiotics should NOT be used as initial therapy for uncomplicated otitis externa 1, 4
• Reserve oral antibiotics for specific circumstances:
  • Extension of infection beyond the ear canal 4
  • Patients with diabetes or immunocompromised status 4, 1
  • When topical therapy cannot reach the infected area or has failed 1, 4
• Most oral antibiotics prescribed for otitis externa are inactive against common pathogens like P. aeruginosa 4
• A study showed that topical ciprofloxacin and hydrocortisone is clinically equivalent to the combination of topical neomycin/polymyxin b/hydrocortisone with systemic amoxicillin for treatment of AOE 6

Patient Education

• Instruct patients on proper administration of eardrops: lying down with the affected ear up, filling the ear canal with drops, remaining in position for 3-5 minutes, and applying gentle to-and-fro movement of the ear 1
• Inform patients that symptoms typically improve within 48-72 hours and to complete the full course of therapy even if symptoms resolve early 1, 4
• Keep the ear dry during treatment 1
• Patients should return for reassessment if symptoms don't improve within 48-72 hours 4

Prevention Strategies

• Strategies to reduce recurrence include removing obstructing cerumen, using acidifying ear drops before/after swimming, drying the ear canal with a hair dryer, and using ear plugs while swimming 3, 2

Common Pitfalls to Avoid

• Overuse of oral antibiotics for uncomplicated cases 1, 4
• Using ototoxic preparations when tympanic membrane integrity is compromised 1, 4
• Inadequate pain management 1, 3
• Failure to remove debris before administering drops 1, 4
• Missing fungal infections, especially in patients with diabetes or those who fail to respond to antibacterial therapy 1, 4