What is the recommended management for otitis externa?

Management of Acute Otitis Externa

First-Line Treatment: Topical Antimicrobial Therapy

Topical antimicrobial drops are the definitive first-line treatment for uncomplicated acute otitis externa—oral antibiotics should NOT be used initially. 1, 2 Topical therapy achieves drug concentrations 100-1000 times higher than systemic antibiotics at the infection site and demonstrates superior clinical cure rates of 77-96% versus only 30-67% with oral antibiotics. 2

Selecting the Appropriate Topical Agent

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

When tympanic membrane is perforated, uncertain, or tympanostomy tubes are present:

• Use ONLY non-ototoxic fluoroquinolone preparations 1, 2
• Ofloxacin 0.3% otic solution: 10 drops once daily for 7 days (patients ≥13 years); 5 drops once daily for 7 days (ages 6 months-13 years) 3
• Ciprofloxacin 0.2% otic solution: 0.25 mL twice daily for 7 days 4
• Never use aminoglycoside-containing drops (neomycin/polymyxin B) due to ototoxicity risk 1, 2

When tympanic membrane is intact:

• Any FDA-approved topical preparation is acceptable, as all achieve 65-90% clinical cure rates within 7-10 days 1, 2
• Neomycin/polymyxin B/hydrocortisone is a reasonable first-line option 5
• Ofloxacin 0.3% provides once-daily dosing convenience and superior microbiological eradication 1, 6
• Avoid neomycin-containing preparations in patients with history of contact dermatitis (affects 5-15% of patients with chronic otitis externa) 1, 2

Essential Pre-Treatment Step: Aural Toilet

Before administering any drops, the ear canal MUST be cleared of debris, cerumen, and inflammatory material to ensure medication reaches infected tissues. 7, 1, 2

Cleaning methods include:

• Gentle suction or dry mopping (preferred method) 1, 2
• Irrigation with body-temperature water, saline, or hydrogen peroxide 1
• In diabetic or immunocompromised patients: avoid aggressive irrigation and use only atraumatic suctioning under microscopic guidance, as irrigation has been implicated in triggering necrotizing otitis externa 1, 2

Proper Drop Administration Technique

Only 40% of patients self-administer drops correctly during the first 3 days, so explicit instruction is critical 2:

• Warm the bottle in hands for 1-2 minutes to prevent dizziness 7, 4, 3
• Have someone else administer drops if possible (significantly improves adherence) 7, 2
• Lie with affected ear upward 7, 4, 3
• Instill enough drops to fill the ear canal 7
• Maintain this position for 3-5 minutes (use a timer) 7, 1
• Apply gentle to-and-fro movement of the pinna or press the tragus with in/out motion to eliminate trapped air 7, 2

Wick Placement

Place an ear wick when canal edema prevents drop entry or when most of the tympanic membrane cannot be visualized. 7, 1 The wick may fall out spontaneously as inflammation resolves—this is a positive sign. 7

Pain Management

Pain assessment and appropriate analgesic therapy is essential, as pain in acute otitis externa is often severe and disproportionate to visual findings. 1, 2

• Prescribe acetaminophen or NSAIDs based on pain severity 1, 2
• Inform patients that pain typically improves within 48-72 hours of starting treatment 7, 1, 2
• NSAIDs administered during the acute phase significantly reduce pain compared to placebo 2
• Do NOT use topical anesthetic drops (benzocaine)—they are not FDA-approved for active ear canal infections and can mask delayed treatment response 2

Treatment Duration and Follow-Up

Continue eardrops for a minimum of 7 days, even if symptoms resolve earlier, to prevent relapse. 1, 2 If symptoms persist beyond 7 days, continue drops until symptoms resolve for a maximum of 7 additional days (total 14 days maximum). 1, 2

Reassess the patient if no improvement occurs within 48-72 hours. 1, 2 Consider the following causes of treatment failure:

• Inadequate drug delivery due to canal obstruction 1, 2
• Poor adherence to therapy (patients tend to overadminister when pain is greatest and underadminister as symptoms resolve) 2
• Fungal co-infection (otomycosis) 1, 2
• Allergic contact dermatitis from topical agents 1, 2
• Incorrect diagnosis 1, 2

When to Use Systemic Antibiotics

Reserve oral antibiotics for specific circumstances ONLY—they should NOT be used for uncomplicated acute otitis externa. 1, 2 Approximately 20-40% of patients inappropriately receive oral antibiotics, and most prescribed oral antibiotics are inactive against the primary pathogens Pseudomonas aeruginosa and Staphylococcus aureus. 2

Indications for systemic antibiotics:

• Extension of infection beyond the ear canal 1, 2
• Diabetes mellitus or immunocompromised status 1, 2
• Topical therapy cannot reach the infected area 1, 2
• Treatment failure after 48-72 hours of appropriate topical therapy 2

When systemic antibiotics are indicated, use fluoroquinolones (e.g., ciprofloxacin) for coverage against P. aeruginosa and S. aureus. 1, 2

Special Populations Requiring Modified Management

Diabetic or Immunocompromised Patients

These patients require heightened vigilance and modified management due to risk of necrotizing otitis externa. 1, 2

• Avoid aggressive ear canal irrigation—use only atraumatic suctioning 1, 2
• Monitor carefully for signs of necrotizing otitis externa (can present initially with symptoms similar to uncomplicated otitis externa) 1, 2
• Consider adding systemic fluoroquinolone antibiotics in addition to topical therapy 1, 2
• Higher susceptibility to fungal infection (otomycosis)—if suspected, use topical antifungal therapy and debridement, avoiding antibacterial drops that promote fungal overgrowth 1, 2

Patients with Prior Ear Surgery or Tympanostomy Tubes

Use only non-ototoxic fluoroquinolone preparations (ofloxacin 0.3% or ciprofloxacin 0.2%). 1, 2

Activity Restrictions and Patient Education

• Keep the ear dry during treatment 7, 1
• Cover the ear canal opening with an earplug or petroleum jelly-coated cotton before showering or hair washing 1
• Avoid scratching or touching the ear; do NOT insert cotton-tipped swabs or any objects into the ear canal 1, 2
• Consult with physician regarding swimming or water activities during or after infection 1
• If you taste the eardrops, inform your doctor immediately—this indicates a tympanic membrane perforation 7

Common Pitfalls to Avoid

• Prescribing oral antibiotics for uncomplicated cases 1, 2
• Using ototoxic aminoglycoside preparations when tympanic membrane integrity is compromised 1, 2
• Inadequate pain management 1, 2
• Failure to remove debris before administering drops 1, 2
• Missing fungal infections, especially in diabetic patients or those failing antibacterial therapy 1, 2
• Inadequate treatment duration (stopping drops when symptoms improve before completing 7 days) 1, 2

Alternative Therapies to Avoid

Ear candles should NEVER be used—they have never been shown to be effective but have caused harm including ear canal obstruction with paraffin, hearing loss, and tympanic membrane perforation. 7