Inflammatory / infectious / autoimmune / systemic disorders

Necrotizing malignant external otitis

Last author update: 1 October 2013
Last staff update: 14 December 2020

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PubMed Search: Necrotizing malignant external otitis

Nat Pernick, M.D.
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Cite this page: Pernick N. Necrotizing malignant external otitis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/earnecrotizingotitis.html. Accessed June 3rd, 2023.
Definition / general
  • Potentially fatal external otitis due to Pseudomonas aeruginosa (Ann Otolaryngol Chir Cervicofac 2000;117:291), Aspergillus or other fungal infection
  • Usually older patients, often with diabetes, chronic debilitation or immunodeficiency; also undernourished African infants (Rev Laryngol Otol Rhinol 2002;123:225)
  • Initially affects external auditory canal with symptoms of acute otitis externa; later pain, purulent otorrhea and swelling; may progress to cellulitis, chondritis, osteomyelitis (Rev Stomatol Chir Maxillofac 2006;107:167), involve middle ear space or base of skull, and cause cranial nerve palsies, meningitis, venous thrombosis or brain abscess
  • Up to 75% mortality if treatment is delayed
  • Due to tissue ischemia (from above primary pathologic state) plus neutrophilic migratory defect plus virulence of Pseudomonas
Case reports
Gross description
  • Ulcerated skin near osseous portion of external auditory canal, often with abundant necrotic and granulation tissue
Microscopic (histologic) description
  • Epithelium is necrotic or ulcerated with pseudoepitheliomatous hyperplasia, marked mixed inflammatory infiltrate in subcutaneous tissue, necrotizing vasculitis
  • Necrotic bone and cartilage with heavy inflammatory infiltrate in viable bone
  • Variable sequestra of nonviable bone or cartilage
Positive stains
  • Gram stain (gram negative rods)
Differential diagnosis
Additional references
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