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Published on: February 9, 2011
Necrotizing 'malignant' external otitis caused by Staphylococcus epidermidis
1Department of Otolaryngology, Manhattan Eye, Ear, and Throat Hospital, New York, NY 10021.
Abstract:
Necrotizing "malignant" external otitis is a life-threatening skull base infection that originates in the external auditory canal and is characterized by otalgia and purulent aural discharge with external auditory canal cellulitis and granulation. Necrotizing external otitis, seen almost exclusively in elderly diabetics, is almost always caused by Pseudomonas aeruginosa. To our knowledge, there have been only six nonpseudomonal cases reported to date. We describe a 70-year-old diabetic man with necrotizing external otitis caused by Staphylococcus epidermidis, confirmed by serial cultures. This case was characterized by otalgia, purulent otorrhea, preauricular swelling, bony external auditory canal erosion, and a conductive hearing loss. Despite prolonged intravenous antistaphylococcal antibiotic therapy and frequent local débridement, the patient's symptoms never completely resolved. As demonstrated by the treatment failure, S epidermidis necrotizing external otitis, may represent a more refractory form of this already virulent disease process. We believe this to be the first reported case of necrotizing external malignant otitis caused by S epidermidis.
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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