Necrotizing 'malignant' external otitis caused by Staphylococcus epidermidis

H N Barrow1, M J Levenson

  • 1Department of Otolaryngology, Manhattan Eye, Ear, and Throat Hospital, New York, NY 10021.

Insights

Necrotizing external otitis, a severe skull base infection, is typically caused by Pseudomonas aeruginosa. This report details a rare case of this infection caused by Staphylococcus epidermidis in a diabetic patient.

Area of Science:

  • Infectious Diseases
  • Otolaryngology
  • Microbiology

Background:

  • Necrotizing external otitis (NEO) is a severe skull base infection originating in the external auditory canal.
  • NEO predominantly affects elderly diabetic patients and is most commonly caused by Pseudomonas aeruginosa.
  • Non-pseudomonal cases of NEO are exceptionally rare, with only six previously reported instances.

Observation:

  • A 70-year-old diabetic male presented with symptoms of NEO, including otalgia, purulent otorrhea, and preauricular swelling.
  • Diagnostic cultures confirmed the causative agent as Staphylococcus epidermidis.
  • Clinical presentation included bony erosion of the external auditory canal and conductive hearing loss.

Findings:

  • This case represents the first documented instance of necrotizing external malignant otitis caused by Staphylococcus epidermidis.
  • The patient's condition was refractory to prolonged intravenous antistaphylococcal antibiotics and local debridement.
  • Treatment failure suggests that Staphylococcus epidermidis-induced NEO may be a more resistant form of the disease.

Implications:

  • The findings expand the known microbial spectrum of necrotizing external otitis.
  • This case highlights the potential for Staphylococcus epidermidis to cause severe, refractory skull base infections.
  • Further research is warranted to understand the pathogenicity and optimal treatment strategies for non-pseudomonal NEO.

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