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Malignant (necrotizing) external otitis

Jennifer Rubin Grandis, MD
Victor L Yu, MD
Section Editors
Stephen B Calderwood, MD
Morven S Edwards, MD
Deputy Editor
Allyson Bloom, MD


Malignant (necrotizing) external otitis (also termed malignant otitis externa) is an invasive infection of the external auditory canal and skull base, which typically occurs in elderly patients with diabetes mellitus. Increasing reports of malignant external otitis in patients infected with the human immunodeficiency virus (HIV) implicate a compromised immune system as a predisposing factor in this disease.

Pseudomonas aeruginosa is nearly always the responsible organism. The widespread use of oral and topical fluoroquinolones for the treatment of otitis may make the isolation of P. aeruginosa more difficult and has contributed to the emergence of P. aeruginosa resistant to ciprofloxacin [1,2].

The epidemiology, pathogenesis, clinical features, and management of malignant external otitis will be reviewed here. The spectrum of ear and eye infections due to P. aeruginosa and other clinical syndromes caused by this pathogen are discussed separately. (See "Pseudomonas aeruginosa infections of the eye, ear, urinary tract, gastrointestinal tract, and central nervous system", section on 'Ear infections' and "Pseudomonas aeruginosa infections of the eye, ear, urinary tract, gastrointestinal tract, and central nervous system", section on 'Eye infections' and "Pseudomonas aeruginosa skin and soft tissue infections" and "Pseudomonas aeruginosa bacteremia and endocarditis" and "Pseudomonas aeruginosa pneumonia".)

An overview of external otitis is also presented separately. (See "External otitis: Pathogenesis, clinical features, and diagnosis".)


Elderly diabetic patients are overwhelmingly the population at risk for malignant external otitis. More than 90 percent of adults with this disease were found to have some form of glucose intolerance in one review [1]. A number of hypotheses have been advanced to explain this predisposition in diabetics including:

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Literature review current through: Oct 2017. | This topic last updated: Feb 22, 2016.
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