Malignant (Necrotising) Otitis Externa

Invasive infection of the bone surrounding the ear canal (i.e. the mastoid and temporal bones)

Aetiology

  • Relatively rare complication of otitis externa
  • Pseudomonas aeruginosa is the most common cause
  • Risk factors - diabetes, and radiotherapy to the head and neck

Clinical presentation

Symptoms

  • Pain and headache, more severe than clinical signs would suggest

Signs

  • Granulation tissue at bone-cartilage junction of ear canal
  • Exposed bone in the ear canal
  • Facial nerve palsy

Investigations

  • Plasma viscosity/CRP
  • Radiological imaging
  • Biopsy and culture to demonstrate extent of the osteitis and its cause

Management

  • Fatal without treatment - osteomyelitis will progressively involve the skull and meninges
  • Treatment includes:
    • Correction of immunosuppression (when possible)
    • Local treatment of the auditory canal (e.g. cleaning and debridement, topical antibiotics)
    • Long-term systemic antibiotic therapy
    • Surgery in selected patients