Ear
Inflammatory / infectious / autoimmune / systemic disorders
Necrotizing malignant external otitis
Author: Nat Pernick, M.D.
Last author update: 1 October 2013
Last staff update: 14 December 2020
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Necrotizing malignant external otitis
Table of Contents
Definition / general | Treatment | Case reports | Gross description | Microscopic (histologic) description | Positive stains | Differential diagnosis | Additional referencesCite 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
Treatment
- Antibiotics, surgical debridement, hyperbaric oxygen (HNO 2003;51:315)
Case reports
- Female patient with calcium oxalate crystal deposition in necrotizing otomycosis caused by Aspergillus niger (Mod Pathol 1993;6:493)
- Patient with necrotizing otitis externa caused by Stenotrophomonas maltophilia (Hautarzt 2003;54:1080)
- 47 year old man with necrotizing external otitis in a patient caused by Klebsiella pneumoniae (Eur Arch Otorhinolaryngol 2006;263:344)
- 58 year old man with necrotizing otitis externa caused byStaphylococcus epidermidis (Eur Arch Otorhinolaryngol 1999;256:439)
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
