A 27-year-old man with three weeks of persistent left ear drainage after an incomplete four‑day course of amoxicillin‑clavulanate and now uniformly erythematous and swollen ear: what is the recommended treatment?

Treatment of Persistent Otorrhea with Auricular Erythema and Swelling After Incomplete Antibiotic Course

This patient requires immediate topical fluoroquinolone therapy (ciprofloxacin-dexamethasone otic drops) for acute otitis externa, NOT oral antibiotics for otitis media.

Critical Diagnostic Distinction

The clinical presentation—three weeks of persistent ear drainage combined with uniformly erythematous and swollen external ear—indicates acute otitis externa (swimmer's ear) rather than acute otitis media 1. The incomplete four-day course of amoxicillin-clavulanate one week ago is irrelevant to the current condition, as the external ear involvement signals a different infection site entirely.

• Acute otitis media presents with middle ear effusion, bulging tympanic membrane, and systemic symptoms (fever, irritability), with drainage only when perforation occurs 1.
• Acute otitis externa presents with external auditory canal inflammation, auricular erythema/swelling, and pain with manipulation of the pinna—exactly matching this patient's presentation 1.

Recommended Treatment Protocol

First-Line Therapy

• Prescribe topical ciprofloxacin-dexamethasone otic drops as the treatment of choice for acute otitis externa with drainage 1.
• The combination provides both antimicrobial coverage against Pseudomonas aeruginosa and Staphylococcus aureus (the predominant pathogens in otitis externa) plus anti-inflammatory effects from the corticosteroid component 1.

Critical Management Steps

• Perform gentle aural toileting to remove debris and purulent material, which improves topical antibiotic penetration 2.
• Instruct the patient to keep the ear dry during treatment—no swimming, and use cotton with petroleum jelly during showering 1.
• Avoid oral antibiotics as they are inferior to topical therapy for otitis externa and unnecessarily expose the patient to systemic side effects 2.

Dosing and Duration

• Administer 4 drops into the affected ear twice daily for 7 days 1.
• If the canal is severely swollen, place a wick to facilitate medication delivery for the first 24–48 hours 1.

Why Oral Antibiotics Are Inappropriate

• Topical antibiotics achieve 100–1000 times higher concentrations in the external auditory canal compared to systemic administration 2.
• A Cochrane review found that topical quinolones are significantly more effective than systemic antibiotics for ear discharge (RR 1.48,95% CI 1.24–1.76) 2.
• Continuing or restarting amoxicillin-clavulanate would be ineffective because it does not adequately cover Pseudomonas, the most common pathogen in otitis externa 3, 2.

Reassessment Timeline

• Re-evaluate at 48–72 hours to confirm clinical improvement (reduced pain, decreased swelling, less drainage) 1.
• If symptoms worsen or fail to improve, consider:
  • Fungal superinfection (especially if the patient has diabetes or immunocompromise)—treat with topical antifungal drops 1.
  • Malignant otitis externa (rare in immunocompetent adults)—requires urgent ENT referral and IV antibiotics 1.

Common Pitfalls to Avoid

• Do not prescribe ototoxic aminoglycoside drops (gentamicin, neomycin) when tympanic membrane integrity is uncertain, as perforation may be present given the three-week duration of drainage 1.
• Do not assume this is treatment failure of acute otitis media requiring escalation to ceftriaxone or other systemic agents—the external ear involvement indicates a completely different infection 4, 1.
• Do not use oral antibiotics as monotherapy for otitis externa, as they are contraindicated and ineffective compared to topical therapy 1, 2.