What is the recommended treatment for otitis externa?

Treatment of Otitis Externa

Topical antimicrobial therapy is the first-line treatment for uncomplicated acute otitis externa (AOE), delivering concentrations 100-1000 times higher than systemic therapy and effectively targeting common pathogens like Pseudomonas aeruginosa and Staphylococcus aureus. 1, 2

First-Line Treatment Approach

• Aural toilet (gentle suction, dry mopping, irrigation, or removal of obstructing debris) should be performed before administering drops to ensure medication reaches infected tissues 2
• Various topical preparations are effective for treating AOE, including those containing antibiotics (aminoglycosides, polymyxin B, quinolones), steroids, or low-pH antiseptics 1
• 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 with or without steroids 1
• For patients with non-intact tympanic membranes (perforation or tympanostomy tubes), non-ototoxic preparations such as quinolones should be used 1, 2

Pain Management

• Assess patients with AOE for pain and recommend analgesic treatment based on pain severity 1, 2
• Pain typically improves within 48-72 hours of starting appropriate treatment 1, 2

Special Considerations

Patients with Diabetes or Immunocompromised Status

• These patients require special consideration as they are susceptible to otomycosis and necrotizing otitis externa 1, 3
• Monitor more carefully for signs of necrotizing otitis externa, which can present initially with symptoms similar to uncomplicated otitis externa 2
• Consider systemic antibiotics in addition to topical therapy 2

Fungal Infections

• If fungal infection is suspected, especially in patients with diabetes or those who fail to respond to antibacterial therapy, topical antifungal therapy and debridement are recommended 2
• Avoid antibacterial drops that may promote fungal overgrowth 2

When to Use Systemic Antibiotics

• Systemic antibiotics should NOT be prescribed as initial therapy for uncomplicated AOE 1, 2, 3
• Oral antibiotics should be reserved for specific circumstances:
  • Extension of infection beyond the ear canal 1, 2
  • Patients with diabetes or immunocompromised status 1, 2
  • When topical therapy cannot reach the infected area or has failed 1, 2

Proper Administration Technique

• Have the patient lie with the affected ear upward, administer drops along the side of the ear canal until it is filled, and have the patient remain in this position for 3-5 minutes 3
• Gentle to-and-fro movement of the pinna may be necessary to eliminate trapped air 3

Treatment Expectations and Follow-up

• Patients should expect improvement within 48-72 hours of initiating appropriate topical therapy 1, 2, 3
• If no improvement occurs within this timeframe, consider:
  • Treatment failure 1, 3
  • Allergic contact dermatitis 1, 3
  • Misdiagnosis 1, 3
  • Fungal co-infection 3

Prevention Strategies

• Strategies to reduce recurrence include:
  • Removing obstructing cerumen 1
  • Using acidifying ear drops before/after swimming 1
  • Drying the ear canal with a hair dryer 1
  • Using ear plugs while swimming 1

Common Pitfalls to Avoid

• Overuse of oral antibiotics for uncomplicated cases 1, 2
• Using ototoxic preparations (like neomycin) when tympanic membrane integrity is compromised 1, 2, 4
• Inadequate pain management 1, 2
• Failure to remove debris before administering drops 1, 2
• Missing fungal infections, especially in patients with diabetes or those who fail to respond to antibacterial therapy 1, 2
• Neomycin has been associated with contact sensitivity in 13-30% of patients with chronic otitis externa 3
• Prolonged use of antibiotic preparations may result in overgrowth of nonsusceptible organisms, including fungi 4, 5

Emerging Concerns

• Studies have shown declining susceptibility to neomycin and polymyxin B among pathogens recovered in otitis externa 6
• Quinolone preparations (such as ofloxacin) have maintained effectiveness and may be preferable in cases where resistance is suspected 6, 7