Article Sections

Introduction

Necrotizing (malignant) otitis externa (NOE) is a severe, life-threatening complication of otitis externa that most commonly affects elderly patients with diabetes mellitus.  NOE occurs when the causative pathogen, almost always Pseudomonas aeruginosa, invades the external ear canal and extends to the skull base and temporal bone.

Pathophysiology

NOE occurs as a complication of otitis externa ( Table 1) and appears to overwhelmingly affect elderly patients with diabetes mellitus or other immunocompromising conditions (eg, HIV, immunosuppressive therapy).

Because NOE typically does not occur in healthy individuals, it is likely the combination of predisposing host factors (eg, microangiopathy and increased pH in the external ear canal in diabetes mellitus) and virulence factors (eg, proteases that can cause soft tissue damage) of P aeruginosa (the causative organism in >95% of cases) that allows for the pathogen to invade.  Without an adequate immune response,

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Tables

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