What is the treatment for otitis externa (swimmer's ear)?

Treatment of Otitis Externa (Swimmer's Ear)

Topical antimicrobial ear drops are the first-line and definitive treatment for uncomplicated acute otitis externa, delivering concentrations 100-1000 times higher than oral antibiotics and effectively targeting the causative pathogens Pseudomonas aeruginosa and Staphylococcus aureus. 1, 2

Initial Assessment

Before initiating treatment, assess for modifying factors that alter management: 1, 3

• Tympanic membrane status (perforation or tympanostomy tubes present)
• Diabetes mellitus
• Immunocompromised state (HIV/AIDS, chemotherapy, malignancy)
• Prior radiotherapy to the head/neck
• Severity of canal edema (determines need for wick placement)

These factors are critical because they determine medication selection, risk of complications like necrotizing otitis externa, and whether systemic antibiotics are needed. 1

Treatment Algorithm

Step 1: Aural Toilet (Debris Removal)

Perform gentle cleaning of the ear canal to remove inflammatory debris, cerumen, or foreign material before administering drops. 2, 3 This step is essential because debris prevents medication penetration and prolongs healing. 2

Cleaning methods: 2, 3

• Gentle suction (preferred method)
• Dry mopping with cotton applicator
• Irrigation with body-temperature water, saline, or hydrogen peroxide

Critical caveat: In diabetic or immunocompromised patients, avoid irrigation entirely and use only atraumatic aural suctioning, as irrigation may predispose to necrotizing otitis externa. 1, 3

Step 2: Topical Antimicrobial Selection

The choice of ear drops depends entirely on tympanic membrane integrity:

For INTACT Tympanic Membrane:

Use any of the following topical preparations: 1, 2

• Neomycin/polymyxin B/hydrocortisone (reasonable first-line choice) 4
• Ofloxacin 0.3% otic solution 3, 5
• Ciprofloxacin 0.2% otic solution 6
• Acetic acid preparations (effective but less so if treatment extends beyond 1 week) 7

All of these options show comparable clinical cure rates of approximately 88-95%. 5, 7 The addition of topical steroids to antimicrobials may hasten pain relief. 2, 4

For NON-INTACT Tympanic Membrane (Perforation or Tubes):

Use ONLY non-ototoxic quinolone preparations: 2, 3

• Ciprofloxacin 0.2% otic solution 6
• Ofloxacin 0.3% otic solution 3

Never use aminoglycoside-containing drops (neomycin, gentamicin) or polymyxin B in patients with perforated eardrums or tympanostomy tubes, as these are ototoxic. 2, 3

Step 3: Wick Placement (If Needed)

Place an ear canal wick if: 2, 3

• Severe edema prevents drop entry into the canal
• Most of the tympanic membrane cannot be visualized due to swelling

The wick ensures medication delivery to the infected area when the canal is too swollen for drops to penetrate. 2

Step 4: Dosing Instructions

Proper administration is critical for treatment success: 1, 3

• Patient positioning: Lie with affected ear upward 1, 3
• Instill drops: Fill the ear canal completely 1, 3
• Remain in position: Stay lying down for 3-5 minutes (use a timer) 1, 3
• Facilitate penetration: Apply gentle to-and-fro movement of the ear or press the tragus in/out 1, 3
• Frequency: Twice daily for ciprofloxacin 6; once daily for ofloxacin 5
• Duration: Minimum 7 days, even if symptoms resolve earlier 1, 3

Step 5: Pain Management

Prescribe analgesics based on pain severity—this is a critical component often overlooked. 1, 2

• Mild to moderate pain: NSAIDs or acetaminophen 2
• Severe pain: Consider short-term opioid-containing analgesics for the initial 48-72 hours 2

Inform patients that pain typically improves within 48-72 hours of starting treatment. 1, 2, 3 If pain persists beyond this timeframe, reevaluation is needed. 1

Do NOT use anesthetic ear drops during active infection—they can mask treatment failure. 1

When to Use Systemic Antibiotics

Oral antibiotics should NOT be used as initial therapy for uncomplicated otitis externa. 1, 2, 3 They are inactive against P. aeruginosa and S. aureus, have systemic side effects, and promote antibiotic resistance. 1

Reserve oral antibiotics for specific circumstances only: 2, 3

• Extension of infection beyond the ear canal (cellulitis, lymphadenitis) 1, 4
• Diabetic or immunocompromised patients (consider adding to topical therapy) 1, 2, 3
• Topical therapy cannot reach the infected area 2
• Treatment failure after appropriate topical therapy 2

Special Populations

Diabetic or Immunocompromised Patients

These patients require heightened vigilance for necrotizing (malignant) otitis externa, a life-threatening skull base osteomyelitis. 1, 3

Management modifications: 1, 3

• Avoid ear canal irrigation (use only atraumatic suction) 1, 3
• Consider adding systemic antibiotics to topical therapy 2, 3
• Monitor closely for warning signs: granulation tissue at bony-cartilaginous junction, facial nerve paralysis, persistent severe pain 1
• Lower threshold for imaging (CT/MRI) if symptoms persist or worsen 1

Fungal Otitis Externa (Otomycosis)

Suspect fungal infection in patients with diabetes or those failing antibacterial therapy. 2, 3

Management: 3

• Topical antifungal therapy plus debridement
• Discontinue antibacterial drops that promote fungal overgrowth

Patient Education and Activity Restrictions

During treatment: 1, 3

• Keep the ear dry 1, 2
• Cover ear canal opening with earplug or petroleum jelly-coated cotton before showering 1, 3
• Avoid scratching or inserting anything into the ear canal (including cotton swabs) 1, 3
• Consult physician before resuming swimming or water activities 1, 3

Complete the full 7-day course even if symptoms resolve earlier to prevent relapse. 1, 3 If symptoms persist beyond 7 days, continue drops until resolution for a maximum of 7 additional days (14 days total). 1, 3

Common Pitfalls to Avoid

• Prescribing oral antibiotics for uncomplicated cases (occurs in 20-40% of cases but is inappropriate) 1, 2
• Using ototoxic preparations when tympanic membrane integrity is unknown or compromised 2, 3
• Inadequate pain management (pain control is as important as antimicrobial therapy) 1, 2
• Failure to remove debris before administering drops (significantly reduces efficacy) 2, 3
• Missing fungal infections in diabetic patients 2, 3
• Irrigating ears in diabetic/immunocompromised patients (increases necrotizing otitis externa risk) 1, 3
• Instructing patients to use drops for a fixed duration without guidance on symptom-based continuation 7

Expected Outcomes

With appropriate topical therapy, clinical cure rates are 88-95%, with most patients experiencing symptom resolution within 48-72 hours and complete cure by 7 days. 1, 2, 5 Approximately 68% of patients are cured within the first 7 days of treatment. 5