Otitis externa — structured clinical encounter

Candidate brief

You are the paediatric registrar in the emergency department. An eight-year-old girl who swims daily presents with two days of worsening right ear pain, a mucky discharge and itching, and cries when the ear is touched. On examination, pressing the tragus and gently pulling the pinna backwards reproduces the pain, the canal is swollen and red with yellowish debris, and once a small amount is cleared the eardrum looks normal. She is afebrile and well. [1]

Task

Take the focused history, present your differential, justify your bedside assessment and your analgesia-led topical-first management, and explain when you would place an ear wick and when you would add an oral antibiotic. Be prepared to defend the avoidance of routine oral antibiotics for uncomplicated disease. A second child — an immunocompromised six-year-old with severe unremitting otalgia and a facial palsy — will then be introduced for contrast. [5]

Discussion anchors

• Localisation and diagnosis: acute diffuse otitis externa (swimmer's ear) from the water-exposure history, otalgia, otorrhoea and pruritus, with tragal tenderness and pain on pinna traction placing the disease in the canal and a cleared view of a normal tympanic membrane excluding acute otitis media. [1]
• Management: analgesia with paracetamol and ibuprofen, aural toilet, a topical antimicrobial with corticosteroid for about seven days, keeping the ear dry and avoiding cotton buds; the 2023 systematic review supports topical-first care with no added benefit from oral antibiotics in uncomplicated disease. [5]
• Ear wick and drop choice: insert an ear wick for two to three days when the canal is too swollen to admit drops; use a fluoroquinolone rather than an aminoglycoside drop when the tympanic membrane may be perforated, because of the ototoxicity concern. [3]
• Contrast case: the immunocompromised six-year-old with severe unremitting otalgia, granulation at the bony-cartilaginous junction and a facial palsy is necrotising otitis externa with skull-base osteomyelitis — admit, biopsy, send CRP and ESR, image the skull base, and give prolonged oral ciprofloxacin 10 to 20 mg per kilogram (maximum 750 mg) every 12 hours or intravenous ceftazidime or cefepime. [7] [9]
• Disposition and safety-net: discharge the well child on topical therapy with a clear safety-net for spreading redness, fever, severe worsening pain or any facial weakness; admit the child with necrotising disease for inpatient systemic therapy and serial inflammatory-marker monitoring. [10]