What is the treatment for otitis externa?

Treatment for 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

Aural Toilet (Essential First Step)

• Remove debris, cerumen, and inflammatory material from the ear canal before administering any drops to ensure medication reaches infected tissues 1, 2
• Use gentle suction, dry mopping (cotton-tipped applicator), or irrigation with body-temperature water, saline, or hydrogen peroxide 3, 1
• Critical caveat: Avoid aggressive irrigation in diabetic or immunocompromised patients, as this has been implicated in triggering malignant (necrotizing) otitis externa; use atraumatic suctioning under microscopic guidance instead 3

Wick Placement (When Needed)

• Place a compressed cellulose wick if severe canal edema prevents drop entry or if the tympanic membrane cannot be visualized 3, 1
• The wick expands when moistened, facilitating drug delivery and reducing edema 3
• Remove the wick once edema subsides, typically within 24 hours 3

Topical Antimicrobial Selection

When Tympanic Membrane is Intact or Certain

• Any FDA-approved topical preparation is acceptable, including: 1, 2
  • Neomycin/polymyxin B/hydrocortisone (4 times daily)
  • Ciprofloxacin/dexamethasone
  • Ofloxacin 0.3% (once or twice daily)
• All agents achieve equivalent clinical cure rates of 65-90%, so choose based on cost, dosing frequency, and patient preference 1, 4
• Neomycin-containing preparations cause contact dermatitis in 5-15% of patients with chronic otitis externa, so avoid if prior sensitivity 1, 2

When Tympanic Membrane is Perforated, Uncertain, or Tympanostomy Tubes Present

• Use ONLY non-ototoxic fluoroquinolone preparations: 1, 2
  • Ofloxacin 0.3% (preferred)
  • Ciprofloxacin 0.2%
• Never use aminoglycoside-containing drops (neomycin, gentamicin) in these situations due to ototoxicity risk 1, 2

Treatment Duration and Dosing

• Minimum 7 days of treatment, even if symptoms resolve earlier 1
• Ofloxacin can be dosed once daily for 7 days with 91% cure rates (5 drops for children <13 years, 10 drops for adolescents/adults) 5
• Continue until resolution, maximum 7 additional days if symptoms persist 1

Proper Drop Administration (Critical for Success)

• Only 40% of patients self-administer drops correctly during the first 3 days—having someone else apply drops significantly improves adherence 3
• Warm bottle in hand, lie with affected ear upward, fill canal with drops, maintain position for 3-5 minutes 3, 1
• Use gentle to-and-fro movement of pinna or tragal pumping to eliminate trapped air 3, 2

Pain Management

• Assess pain severity and prescribe appropriate analgesics—pain typically improves within 48-72 hours of starting treatment 1, 2
• Mild-to-moderate pain: acetaminophen or NSAIDs 1
• Severe pain: consider short-term opioid-containing analgesics for initial 48-72 hours 2
• Avoid topical anesthetic drops (benzocaine): not FDA-approved, may mask disease progression, contraindicated with tympanostomy tubes 1

When to Use Systemic Antibiotics

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

Reserve Oral Antibiotics for These Specific Indications:

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

When Systemic Antibiotics Are Indicated:

• Use fluoroquinolones (ciprofloxacin) for coverage against P. aeruginosa and S. aureus, which cause 98% of cases 1
• Most other oral antibiotics are inactive against P. aeruginosa 1

Special Populations Requiring Modified Management

Diabetic or Immunocompromised Patients

• Monitor carefully for necrotizing otitis externa, which can present initially with symptoms identical to uncomplicated otitis externa 1, 2
• Consider adding systemic fluoroquinolones in addition to topical therapy 1, 2
• More susceptible to otomycosis (fungal infection) 1
• Avoid aggressive irrigation; use atraumatic suctioning instead 3

Suspected Fungal Otitis Externa (Otomycosis)

• Treat with topical antifungals and debridement 1
• Avoid antibacterial drops that promote fungal overgrowth 1
• Consider in patients with diabetes or those failing antibacterial therapy 1, 2

Expected Clinical Course and Reassessment

• Symptoms should improve within 48-72 hours of starting appropriate treatment 1, 2
• Reassess if no improvement at 48-72 hours 1, 2

Reasons for Treatment Failure:

• Inadequate drug delivery (canal obstruction, poor adherence) 1, 2
• Fungal co-infection 1, 2
• Allergic contact dermatitis from topical agents (especially neomycin) 1, 2
• Incorrect diagnosis 1
• Patients tend to undermedicate as symptoms improve 1

Common Pitfalls to Avoid

• Overuse of oral antibiotics for uncomplicated cases 1, 2
• Using ototoxic preparations (aminoglycosides) when tympanic membrane integrity is compromised 1, 2
• Failing to remove debris before administering drops, preventing medication from reaching infection site 1, 2
• Inadequate pain management 1, 2
• Missing fungal infections, especially in diabetic patients or those with treatment failure 1, 2
• Aggressive irrigation in diabetic/immunocompromised patients 3

Patient Education

• Complete the full 7-day course even if symptoms resolve early 1, 2
• Keep ear dry during treatment; avoid water exposure 1
• Do not insert cotton swabs or other objects into ear canal 1
• Return for reassessment if no improvement within 48-72 hours 1, 2