What is the recommended treatment for otitis externa?

Treatment of Otitis Externa

Topical antimicrobial therapy is the definitive first-line treatment for uncomplicated acute otitis externa, NOT oral antibiotics, with clinical cure rates of 65-90% within 7-10 days regardless of which specific topical agent is used. 1, 2

Initial Management Steps

Before prescribing any medication, perform aural toilet to remove debris, cerumen, and inflammatory material from the ear canal—this is essential because medication cannot reach infected tissues if the canal is obstructed. 1, 2 Use gentle suction, dry mopping, or irrigation with body-temperature water, saline, or hydrogen peroxide. 1 However, avoid aggressive irrigation in diabetic or immunocompromised patients as this can trigger necrotizing otitis externa; use atraumatic suctioning under microscopic guidance instead. 2

If severe edema prevents drop entry or you cannot visualize most of the tympanic membrane, place a wick in the ear canal to ensure effective delivery of topical preparations. 1

Topical Antimicrobial Selection

The choice of topical preparation depends critically on tympanic membrane integrity: 1, 2

When Tympanic Membrane is Perforated or Uncertain

Use ONLY non-ototoxic fluoroquinolone preparations such as: 1, 2, 3

• Ofloxacin 0.3% otic solution
• Ciprofloxacin 0.2% otic solution

Never use aminoglycoside-containing drops (neomycin, gentamicin) when the tympanic membrane is perforated or its integrity is uncertain, as these are ototoxic and can cause permanent hearing loss. 1, 2

When Tympanic Membrane is Intact

Any FDA-approved topical preparation is acceptable, including: 2

• Fluoroquinolones (ofloxacin, ciprofloxacin)
• Aminoglycoside combinations (neomycin/polymyxin B/hydrocortisone)
• Polymyxin B-based preparations

However, avoid neomycin-containing preparations in patients with a history of contact dermatitis, as neomycin causes allergic reactions in 5-15% of patients with chronic external otitis. 2

Dosing Regimens (FDA-Approved)

Ofloxacin 0.3% for Otitis Externa 4

• Children 6 months to 13 years: 5 drops once daily for 7 days
• Patients ≥13 years: 10 drops once daily for 7 days

Ciprofloxacin 0.2% for Otitis Externa 5

• All ages: 0.25 mL (one single-dose container) twice daily for 7 days

Proper Drop Administration Technique

Only 40% of patients self-administer drops correctly—having someone else apply drops significantly improves adherence. 2 Instruct patients to: 1, 2

1. Warm the bottle in hands for 1-2 minutes to prevent dizziness from cold solution
2. Lie with affected ear upward
3. Fill the ear canal with the prescribed number of drops
4. Maintain position for 3-5 minutes to facilitate penetration
5. Apply gentle to-and-fro movement of the pinna or tragal pumping to eliminate trapped air

Adding Topical Corticosteroids

Adding a topical steroid to antimicrobial drops may hasten pain relief by reducing inflammation, though the evidence is moderate strength. 1 Most combination preparations include hydrocortisone. 1

Pain Management

Pain from otitis externa can be intense due to the highly sensitive periosteum of the underlying bone. 3 Pain typically improves within 48-72 hours of starting appropriate treatment. 1, 2, 3

• Mild to moderate pain: Acetaminophen or NSAIDs 3
• Severe pain: Consider short-term opioid-containing analgesics for the initial 48-72 hours 1, 3

Do NOT use topical anesthetic drops (benzocaine)—they are not FDA-approved for active ear canal infections and can mask delayed treatment response. 2

When Systemic Antibiotics ARE Indicated

Oral antibiotics should NOT be used as initial therapy for uncomplicated otitis externa. 1, 2, 3 Approximately 20-40% of patients inappropriately receive oral antibiotics, which are often inactive against the primary pathogens Pseudomonas aeruginosa and Staphylococcus aureus. 2

Reserve systemic antibiotics for: 1, 2, 3

• Extension of infection beyond the ear canal
• Diabetic patients (higher risk for necrotizing otitis externa)
• Immunocompromised patients
• Topical therapy cannot reach the infected area
• Treatment failure after 48-72 hours

When systemic antibiotics are indicated, use fluoroquinolones (ciprofloxacin orally) for coverage against P. aeruginosa and S. aureus, which cause 98% of cases. 2, 3

Special Populations Requiring Modified Management

Diabetic or Immunocompromised Patients

These patients are at high risk for otomycosis and necrotizing otitis externa, a life-threatening condition. 2, 3, 6

• Monitor carefully for signs of necrotizing otitis externa (severe pain out of proportion to findings, granulation tissue, cranial nerve involvement) 1, 2
• Consider adding systemic antibiotics (fluoroquinolones) in addition to topical therapy 2
• Avoid aggressive irrigation—use atraumatic suctioning instead 2

Patients with Tympanostomy Tubes or Prior Ear Surgery

Use only non-ototoxic fluoroquinolone preparations (ofloxacin or ciprofloxacin). 2, 3

Treatment Duration and Follow-Up

• Minimum treatment duration: 7 days, even if symptoms resolve earlier 2
• If symptoms persist beyond 7 days: Continue drops until resolution for a maximum of 7 additional days (total 14 days maximum) 2
• Reassess within 48-72 hours if no improvement occurs 1, 2

Reasons for Treatment Failure

If no improvement occurs within 48-72 hours, consider: 1, 2

• Inadequate drug delivery due to canal obstruction or debris
• Poor adherence to therapy (patients tend to overadminister when pain is greatest, underadminister as symptoms resolve)
• Fungal co-infection (otomycosis)—especially in diabetic patients
• Allergic contact dermatitis from topical agents (particularly neomycin)
• Incorrect diagnosis

Patient Education and Activity Restrictions

• Keep the ear dry during treatment—cover the ear canal with an earplug or petroleum jelly-coated cotton before showering 2, 3
• Complete the full 7-day course even if symptoms resolve early 1, 2
• If you taste the eardrops, inform your doctor immediately—this indicates tympanic membrane perforation 2
• Do NOT insert cotton swabs or other objects into the ear canal 2
• NEVER use ear candles—they have no proven efficacy and can cause harm including ear canal obstruction, hearing loss, and tympanic membrane perforation 2

Critical Pitfalls to Avoid

1. Overuse of oral antibiotics for uncomplicated cases 1, 2
2. Using ototoxic preparations (aminoglycosides) when tympanic membrane integrity is compromised 1, 2
3. Inadequate pain management 1
4. Failure to remove debris before administering drops 1, 2
5. Missing fungal infections, especially in diabetic patients or those failing antibacterial therapy 1, 2
6. Prescribing aminoglycoside drops when tympanic membrane integrity is unknown 2