What is the recommended treatment for otitis externa?

Treatment of Otitis Externa

Topical antimicrobial ear drops are the definitive first-line treatment for uncomplicated otitis externa—oral antibiotics should not be prescribed initially. 1

Essential Pre-Treatment Step: Aural Toilet

Before administering any medication, the ear canal must be cleared of debris, cerumen, and inflammatory material to ensure drops reach infected tissue. 1, 2 This can be accomplished through:

• Gentle suction, dry mopping, or irrigation with body-temperature water, saline, or hydrogen peroxide in most patients 1
• In diabetic or immunocompromised patients, use only atraumatic suction under microscopic guidance—never irrigate, as this can precipitate necrotizing otitis externa 1, 2
• If severe canal edema prevents drop entry or the tympanic membrane cannot be visualized, place a compressed cellulose wick to facilitate drug delivery 1, 2

Topical Antimicrobial Selection

When Tympanic Membrane Integrity Is Uncertain or Compromised

Use only non-ototoxic fluoroquinolone preparations (ofloxacin 0.3% or ciprofloxacin 0.2%) to avoid inner-ear toxicity. 1, 3 This applies to patients with:

• Known or suspected tympanic membrane perforation 1
• Tympanostomy tubes 1, 2
• Uncertain membrane status 1

Avoid aminoglycoside-containing drops (e.g., neomycin/polymyxin B) in these situations due to documented ototoxicity risk. 1, 4

When Tympanic Membrane Is Intact

Any FDA-approved topical preparation is acceptable—clinical cure rates of 65-90% are achieved within 7-10 days regardless of the specific agent used. 1, 5 Options include:

• Fluoroquinolones (ofloxacin 0.3% or ciprofloxacin 0.2%) 1, 3
• Neomycin/polymyxin B/hydrocortisone 4
• Acetic acid 2% (though less effective if treatment extends beyond 1 week) 1, 5

Topical preparations containing steroids are significantly more effective than placebo (OR 11; 95% CI 2.00-60.57) and accelerate pain relief. 1, 5

Special Consideration: Neomycin Allergy

Avoid neomycin-containing preparations in patients with a history of contact dermatitis or eczema, as neomycin causes contact sensitivity in 13-30% of patients with chronic otitis externa. 1 Use fluoroquinolone-only drops instead. 1

Proper Drop Administration Technique

Only 40% of patients self-administer drops correctly—explicit instruction is essential: 1

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

Treatment Duration

Prescribe drops for a minimum of 7 days, even if symptoms resolve earlier, to prevent relapse. 1, 2, 3 If symptoms persist beyond 7 days, continue drops until resolution for a maximum of 7 additional days (14 days total maximum). 1

Pain Management

Pain assessment and appropriate analgesia are essential, as otitis externa pain is often severe and disproportionate to visual findings: 1, 2, 3

• Mild-to-moderate pain: Acetaminophen 650-1000 mg every 6 hours or ibuprofen 400-600 mg every 6 hours 1, 3
• Severe pain: Short-term opioid-containing analgesics for the initial 48-72 hours 1
• Pain typically improves within 48-72 hours of starting topical therapy 1, 2, 3

Do not use topical anesthetic drops (e.g., benzocaine)—they are not FDA-approved for active infection and may mask treatment failure. 1

When Systemic Antibiotics ARE Indicated

Oral antibiotics are reserved for specific circumstances only—topical therapy achieves cure rates of 77-96% versus only 30-67% for oral antibiotics. 1 Indications include:

• Extension of infection beyond the ear canal (e.g., periauricular cellulitis or swelling) 1, 2
• Diabetes mellitus or immunocompromised status 1, 2, 3
• Severe canal edema preventing adequate topical delivery despite wick placement 1
• Failure to improve after 48-72 hours of appropriate topical therapy 1, 2

When systemic antibiotics are indicated, use fluoroquinolones (e.g., ciprofloxacin 500 mg twice daily) to cover Pseudomonas aeruginosa and Staphylococcus aureus, which cause approximately 98% of cases. 1, 4, 6

Special Populations: Diabetic or Immunocompromised Patients

These patients require modified management: 1, 2, 7

• Monitor closely for necrotizing otitis externa (persistent severe pain, granulation tissue, cranial nerve involvement) 1, 3
• Avoid ear canal irrigation—use only atraumatic suction under microscopy 1, 2
• Consider systemic antibiotics even for seemingly uncomplicated cases due to higher risk of complications 1, 2
• Higher susceptibility to fungal infections (otomycosis)—maintain low threshold for antifungal therapy 1

Reassessment and Treatment Failure

Reassess patients within 48-72 hours if no improvement occurs. 1, 2, 3 Common reasons for treatment failure include:

• Inadequate drug delivery due to canal obstruction or poor adherence 1
• Allergic contact dermatitis from topical agents (especially neomycin or hydrocortisone) 1
• Fungal co-infection (otomycosis), especially in diabetics or after prolonged antibiotic use 1, 2
• Incorrect diagnosis (e.g., chronic suppurative otitis media, necrotizing otitis externa) 1

Patient Education and Activity Restrictions

• Keep the ear dry during treatment—cover the canal with an earplug or petroleum-jelly-coated cotton before showering 1, 2
• Avoid swimming and water exposure until infection resolves 1, 2, 3
• Do not insert cotton swabs or any objects into the ear canal 1, 2
• Complete the full 7-day course even if symptoms improve early 1, 2
• Return for reassessment if symptoms don't improve within 48-72 hours or persist beyond 2 weeks 1, 3
• If you taste the eardrops, inform your doctor immediately—this indicates a tympanic membrane perforation 1

Critical Pitfalls to Avoid

• Prescribing oral antibiotics for uncomplicated cases (occurs inappropriately in 20-40% of patients) 1, 2
• Using ototoxic preparations when tympanic membrane integrity is compromised 1, 2
• Skipping aural toilet before drop administration—medication cannot penetrate through debris 1, 2
• Inadequate pain management 1, 2
• Irrigating the ear canal in diabetic or immunocompromised patients 1, 2
• Missing fungal infections, especially in high-risk patients 1, 2
• Prescribing neomycin-containing drops to patients with eczema or contact dermatitis history 1