What is the likely diagnosis and treatment for unilateral ear itchiness with yellow watery discharge?

Acute Otitis Externa (Swimmer's Ear)

The most likely diagnosis is acute otitis externa, and you should treat with topical antibiotic ear drops (fluoroquinolone or aminoglycoside/polymyxin B combination) for 7-10 days, NOT oral antibiotics. 1, 2

Diagnostic Criteria

Your patient meets the clinical definition of acute otitis externa, which requires at least 1 characteristic symptom AND at least 2 signs 1, 3:

Symptoms present:

• Itchiness (pruritus) 1, 3
• Yellow watery discharge (otorrhea) 1, 3

Signs to confirm on examination:

• Tragal tenderness (push the tragus or pull the pinna—this will be intensely tender and is the hallmark sign) 1
• Ear canal erythema (redness) 1
• Ear canal edema (swelling) 1
• Wet debris in the canal 1, 3

The diagnosis is entirely clinical—imaging is NOT indicated for uncomplicated cases. 1

First-Line Treatment Algorithm

Step 1: Clean the Ear Canal First

Before administering any drops, you MUST remove debris, cerumen, and inflammatory material through gentle suction, dry mopping, or irrigation with body-temperature water. 2 This is essential because medication cannot penetrate through debris to reach infected tissues. 2

• Use atraumatic suctioning under microscopic guidance if available 2
• Avoid aggressive irrigation in diabetic or immunocompromised patients (can trigger necrotizing otitis externa) 2
• Place a compressed cellulose wick if severe canal edema prevents drop entry 2

Step 2: Select Topical Antibiotic Drops

Choice depends on tympanic membrane integrity: 2

If tympanic membrane is intact or you can visualize it:

• Neomycin/polymyxin B/hydrocortisone (cost-effective first choice) 1, 2
• OR ofloxacin 0.3% 2, 4
• OR ciprofloxacin 0.2% 2, 5

If tympanic membrane integrity is uncertain, perforated, or patient has tympanostomy tubes:

• ONLY use non-ototoxic fluoroquinolones: ofloxacin 0.3% or ciprofloxacin 0.2% 1, 2
• NEVER use aminoglycoside-containing drops (neomycin) in this situation due to ototoxicity risk 1, 2

All FDA-approved topical preparations achieve 65-90% clinical cure rates within 7-10 days with no consistent superiority of one agent over another. 2 The key difference is safety with tympanic membrane perforation.

Step 3: Proper Administration Technique

Instruct the patient (or have someone help them): 2

• Warm the bottle in hands for 1-2 minutes to prevent dizziness 2, 4
• Lie with affected ear upward 2, 4
• Instill drops to completely fill the ear canal 2
• Maintain this position for 3-5 minutes (use a timer) 2, 4
• Apply gentle to-and-fro movement of pinna or press tragus in/out to eliminate trapped air 2
• Only 40% of patients self-administer correctly—having someone else apply drops significantly improves adherence 2

Step 4: Dosing Schedule

For ear canal infection (otitis externa): 4, 5

• Ofloxacin: Once daily for 7 days 4
• Ciprofloxacin: Twice daily (12 hours apart) for 7 days 5
• Neomycin/polymyxin B/hydrocortisone: 3-4 times daily for 7-10 days 6, 7

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

Pain Management

Prescribe appropriate analgesics based on pain severity: 2

• Acetaminophen or NSAIDs for mild-to-moderate pain 2
• Short-term opioids for severe pain during initial 48-72 hours 2
• Pain typically improves within 48-72 hours of starting topical therapy 2, 6, 7
• Do NOT use topical anesthetic drops (benzocaine)—they are not FDA-approved for active infections and can mask treatment failure 2

When Oral Antibiotics ARE Indicated

Oral antibiotics should NOT be used for uncomplicated otitis externa. 1, 2 Reserve systemic antibiotics ONLY for: 1, 2

• Extension of infection beyond the ear canal (periauricular cellulitis/swelling) 1, 2
• Diabetes mellitus 1, 2
• Immunocompromised state 1, 2
• Topical therapy cannot reach infected area 1, 2
• Treatment failure after 48-72 hours 2

If systemic antibiotics are needed, use fluoroquinolones (ciprofloxacin) for coverage against Pseudomonas aeruginosa and Staphylococcus aureus (causative organisms in 98% of cases). 2, 6, 7

Reassessment Criteria

Reassess the patient if: 2

• No improvement within 48-72 hours 2
• Symptoms persist beyond 2 weeks 2

Common causes of treatment failure: 2, 3

• Inadequate drug delivery (canal obstruction, poor adherence) 2, 3
• Allergic contact dermatitis from topical agents (especially neomycin—causes reactions in 5-15% of patients) 1, 2
• Fungal co-infection (otomycosis)—suspect if white fuzzy exudate present 2
• Incorrect diagnosis 2, 3

Special Populations Requiring Modified Management

Diabetic or immunocompromised patients: 2

• Higher risk for necrotizing otitis externa 1, 2
• Higher susceptibility to fungal infections 2
• Avoid ear canal irrigation—use atraumatic suctioning only 2
• Consider adding systemic antibiotics even for seemingly uncomplicated cases 2
• Monitor carefully for deep-seated pain and non-resolving symptoms 3

Patients with eczema, seborrhea, or history of contact dermatitis: 1

• Avoid neomycin-containing preparations entirely 1, 2
• Use fluoroquinolone-only drops (ofloxacin or ciprofloxacin) 2
• Neomycin causes contact sensitivity in 13-30% of patients with chronic otitis externa 2

Patient Education

Activity restrictions: 2

• Keep ear dry during treatment 2
• Cover ear canal with earplug or petroleum jelly-coated cotton before showering 2
• Avoid inserting cotton swabs or any objects into ear canal 2
• Check with doctor regarding swimming 2

Warning signs to report immediately: 2

• If you taste the eardrops (indicates tympanic membrane perforation) 2
• Symptoms not improving within 48-72 hours 2
• Worsening pain or swelling outside the ear 2

Complete the full course: 2, 4

• Use drops for at least 7 days even if symptoms resolve 2, 4
• Symptoms typically improve within 48-72 hours but infection may return if treatment stopped early 2, 4

Common Pitfalls to Avoid

• Prescribing oral antibiotics for uncomplicated cases (occurs inappropriately in 20-40% of patients) 2
• Using ototoxic preparations (aminoglycosides) when tympanic membrane integrity is compromised 1, 2
• Failing to clean ear canal before administering drops 2
• Inadequate pain management 2
• Missing fungal infections (especially in diabetics or after antibiotic use) 2
• Prescribing neomycin to patients with eczema or contact dermatitis history 1, 2
• Never use ear candles—they have caused harm including hearing loss and tympanic membrane perforation with no proven benefit 2