How to manage otitis externa?

Management of Otitis Externa

Topical antimicrobial therapy is the definitive first-line treatment for uncomplicated acute otitis externa, achieving clinical cure in 65-90% of patients within 7-10 days, and oral antibiotics should NOT be used for initial treatment. 1

Initial Assessment and Risk Stratification

Before initiating treatment, assess for critical modifying factors that alter management 1:

• Tympanic membrane integrity: If perforated, uncertain, or tympanostomy tubes present, use ONLY non-ototoxic fluoroquinolones (ofloxacin 0.3% or ciprofloxacin 0.2%) 1, 2
• High-risk patients: Diabetes, immunocompromised status, or prior radiotherapy require more aggressive management and careful monitoring for necrotizing otitis externa 1, 3
• Extension beyond ear canal: Periauricular swelling or cellulitis mandates systemic antibiotics 1
• Fungal infection: White fuzzy exudate with pruritus suggests otomycosis, requiring antifungal therapy instead of antibiotics 4, 3

Essential Pre-Treatment Step: Aural Toilet

Perform aural toilet BEFORE administering any drops—this is critical for treatment success. 1

• Use gentle suction, dry mopping, or irrigation with body-temperature water/saline to remove debris, cerumen, and inflammatory material 1
• CRITICAL CAVEAT: In diabetic or immunocompromised patients, avoid irrigation entirely and use only atraumatic suctioning under microscopic guidance, as irrigation can trigger necrotizing otitis externa 1, 5
• If severe canal edema prevents drop entry or tympanic membrane visualization, place a compressed cellulose wick that expands with moisture to facilitate drug delivery 1

First-Line Topical Therapy Selection

When Tympanic Membrane is Intact:

Any FDA-approved topical preparation is acceptable 1:

• Ofloxacin 0.3%: Once daily dosing (5 drops for ages 6 months-13 years; 10 drops for ≥13 years) for 7 days 2, 6
• Ciprofloxacin 0.2%: Twice daily for 7 days 7
• Neomycin/polymyxin B/hydrocortisone: 3-4 drops 3-4 times daily for 7-10 days 8

All topical agents achieve equivalent cure rates (65-90%), so choose based on cost, dosing frequency, and patient preference. 1

When Tympanic Membrane is Perforated or Uncertain:

Use ONLY non-ototoxic fluoroquinolones 1:

• Ofloxacin 0.3% (preferred for once-daily dosing) 1, 2
• Ciprofloxacin 0.2% 1, 7
• NEVER use aminoglycoside-containing drops (neomycin) due to ototoxicity risk 1

Special Consideration for Neomycin:

Avoid neomycin-containing preparations if history of contact dermatitis exists, as neomycin causes allergic reactions in 5-15% of patients with chronic otitis externa 1

Proper Drop Administration Technique

Only 40% of patients self-administer drops correctly—proper technique is essential for treatment success. 1

Instruct patients to 1, 2:

1. Warm bottle in hand for 1-2 minutes to prevent dizziness
2. Lie with affected ear upward
3. Fill ear canal completely with prescribed drops
4. Apply gentle tragal pumping or to-and-fro pinna movement to eliminate trapped air
5. Maintain position for 5 minutes to allow penetration
6. Leave canal open to air after administration—do NOT plug with cotton

Having someone else administer drops significantly improves adherence. 1

Pain Management

Pain assessment and appropriate analgesic therapy is essential, as otitis externa pain can be severe. 4, 1

• Mild-to-moderate pain: Acetaminophen or NSAIDs (ibuprofen) alone or in combination with opioids 4, 1
• NSAIDs administered during acute phase significantly reduce pain compared to placebo 4
• Pain typically improves within 48-72 hours of starting topical therapy 1
• Do NOT use topical anesthetic drops (benzocaine)—they are not FDA-approved for active infections and can mask treatment failure 1

Activity Restrictions During Treatment

• Keep ear dry throughout treatment course 1
• Cover ear canal with earplug or petroleum jelly-coated cotton before showering 1
• Avoid inserting cotton swabs or other objects into ear canal 1
• If patient tastes eardrops, this indicates tympanic membrane perforation—notify physician immediately 1

When to Use Systemic Antibiotics

Oral antibiotics are NOT indicated for uncomplicated otitis externa and are inappropriately prescribed in 20-40% of cases. 1 Reserve systemic therapy for 1:

• Extension of infection beyond ear canal (periauricular cellulitis/swelling)
• Diabetes mellitus or immunocompromised status
• Topical therapy cannot reach infected area despite wick placement
• Treatment failure after 48-72 hours of appropriate topical therapy

When systemic antibiotics are indicated, use fluoroquinolones (ciprofloxacin) for coverage against Pseudomonas aeruginosa and Staphylococcus aureus, which cause 98% of cases. 1

Management of Fungal Otitis Externa (Otomycosis)

Suspect fungal infection if 4, 3:

• White fuzzy exudate with pruritus and discharge
• Failure to respond to initial antibacterial therapy
• Patient has diabetes or is immunocompromised

Treatment approach 4, 3:

• Thorough but gentle debridement of fungal debris
• Topical antifungal preparations 3-4 times daily for 7-10 days
• NEVER use topical antibiotics—they are ineffective and promote further fungal overgrowth 4
• Add systemic antifungal therapy if diabetic, immunocompromised, or infection extends beyond canal 3

Expected Clinical Course and Reassessment

• Pain improves within 48-72 hours 1
• Clinical resolution occurs within 7-10 days 1, 6
• Complete full 7-day course even if symptoms resolve earlier to prevent relapse 1
• If symptoms persist beyond 7 days, continue drops for maximum 7 additional days (14 days total maximum) 1

Reassess within 48-72 hours if no improvement occurs. 1 Consider treatment failure causes 1:

• Inadequate drug delivery due to canal obstruction or debris
• Poor adherence to therapy
• Fungal co-infection (especially in diabetics or after antibiotic use)
• Allergic contact dermatitis from topical agents (particularly neomycin or hydrocortisone, occurring in 5-15% of patients)
• Incorrect diagnosis

High-Risk Patients: Diabetes and Immunocompromised

These patients require modified management due to risk of necrotizing otitis externa. 1, 3

• Use atraumatic suctioning under microscopic guidance—NEVER irrigate 1, 5
• Consider adding systemic antibiotics even for uncomplicated cases 1
• Monitor carefully for signs of necrotizing otitis externa: persistent severe pain, granulation tissue, cranial nerve involvement 3
• Reassess within 48-72 hours if symptoms worsen or fail to improve 3
• Consider imaging if treatment failure occurs 3

Common Pitfalls to Avoid

• Prescribing oral antibiotics for uncomplicated cases (occurs in 20-40% of patients inappropriately) 1
• Using ototoxic aminoglycoside preparations when tympanic membrane integrity is uncertain 1
• Inadequate pain management during first 48-72 hours 4, 1
• Failure to remove debris before administering drops 1
• Missing fungal infections, especially in diabetics or treatment failures 1, 3
• Irrigating ear canals in diabetic or immunocompromised patients 1, 5
• Discontinuing therapy early when symptoms improve 1