Swimmer's Ear

Swimmer's ear (acute otitis externa) is inflammation or infection of the external auditory canal skin, usually bacterial, precipitated by moisture, trauma or skin disease.

• Pseudomonas aeruginosa (about 40 percent) and Staphylococcus aureus are the commonest bacteria. Fungi (Aspergillus, Candida) cause about 10 percent.
• Risk factors: swimming, humid climates, ear canal trauma (cotton buds, fingernails), hearing aids, earplugs, eczema, narrow canals and diabetes.
• Malignant (necrotising) otitis externa is a life-threatening skull base osteomyelitis in elderly diabetic or immunocompromised patients.
• Peak age is 7 to 12 years.

Pain is the hallmark.

• Ear pain, severe and worse on moving the pinna or pressing on the tragus.
• Itching, fullness and a feeling of blocked ear, hearing loss from canal swelling.
• Otorrhoea, which may be clear, purulent or fungal debris.
• Otoscopy: canal erythema, swelling and debris; the drum may be hidden.
• Fever and periauricular cellulitis or lymphadenopathy in severe cases.
• Differential diagnosis: acute otitis media with perforation, furuncle, herpes zoster oticus (Ramsay Hunt syndrome), eczema, referred pain (dental, temporomandibular joint), foreign body, cholesteatoma and malignant otitis externa.
• Complications: canal stenosis, perichondritis, cellulitis, hearing loss, chronic otitis externa, and malignant otitis externa with cranial nerve palsies (especially facial).

Diagnosis is clinical.

• Pain on pulling the pinna or pressing the tragus.
• Otoscopy and microscopy after gentle cleaning of the canal (aural toilet).
• Swab for culture if the infection is severe, recurrent, resistant or in an immunocompromised patient.
• Blood glucose for diabetes in recurrent cases.
• In suspected malignant otitis externa (severe night pain, granulation tissue at the bony-cartilaginous junction, cranial nerve palsy): erythrocyte sedimentation rate, C-reactive protein, culture, and computed tomography or MRI of the skull base.

Aural toilet, topical therapy and analgesia.

• Supportive: keep the ear dry, avoid cotton buds and scratching, do not swim for 7 to 10 days, and use a cotton ball with petroleum jelly while showering. If the drum is perforated, use only drops that are safe for the middle ear (ciprofloxacin or ofloxacin).
• Aural toilet: gentle suction or dry mopping of debris under microscope.
• Pharmacological, topical (3 to 5 drops three to four times daily for 7 to 10 days): ciprofloxacin 0.3 percent drops (safe if the drum is perforated), or ofloxacin 0.3 percent drops, or neomycin-polymyxin-hydrocortisone drops (avoid if perforation). Acetic acid 2 percent drops are an alternative in mild disease. Dexamethasone or hydrocortisone-containing preparations reduce swelling.
• Insert a wick (Pope wick) if the canal is swollen shut, and soak with drops.
• Analgesia: paracetamol 1 g every 6 hours (children 15 mg/kg), ibuprofen 400 mg every 8 hours (children 5 to 10 mg/kg).
• Systemic antibiotics only for cellulitis, fever, immunocompromise, diabetes or spread beyond the canal: ciprofloxacin 500 mg twice daily (adults; children 10 to 15 mg/kg twice daily) for 7 days, or flucloxacillin 500 mg four times daily for staphylococcal cellulitis.
• Fungal otitis externa: clotrimazole 1 percent drops three times daily for 2 weeks after thorough cleaning.
• Malignant otitis externa: prolonged intravenous antipseudomonal therapy (ciprofloxacin 400 mg every 8 to 12 hours intravenously, or ceftazidime 2 g every 8 hours) for 6 to 12 weeks, with glucose control and surgical debridement.
• Special groups: diabetic, elderly and immunocompromised patients need early specialist review.
• Red flags: severe pain at night, facial nerve palsy, granulation tissue, no improvement in 48 to 72 hours, spreading cellulitis and diabetes.
• Follow-up: review at 48 to 72 hours if not improving, then at 7 to 14 days. Prevent recurrence with ear protection and prophylactic acetic acid drops after swimming.