Stenotrophomonas skull base osteomyelitis presenting as necrotizing otitis externa: Unmasking by CT and MRI-case...

Area of Science:

• Otolaryngology
• Infectious Diseases
• Radiology

Background:

• Necrotizing otitis externa (NOE) can be a subtle presentation of skull-base osteomyelitis (SBO).
• Computed tomography (CT) and magnetic resonance imaging (MRI) are crucial for diagnosing SBO, often revealing discrepancies between mild clinical findings and extensive disease.
• Pseudomonas aeruginosa is the most common pathogen, but other bacteria and fungi can also cause SBO.

Observation:

• This report details a rare case of SBO in an elderly diabetic patient.
• The causative pathogen identified was Stenotrophomonas maltophilia, a bacterium not previously reported in association with SBO.
• Imaging hallmarks include inflammatory changes and bone erosion at the skull base, potentially presenting as the "Ovoid Gap" sign.

Findings:

• Isolation of Stenotrophomonas maltophilia from a patient with skull-base osteomyelitis.
• Demonstration of clinical-imaging discrepancy in a case of necrotizing otitis externa.
• Identification of SBO in an elderly diabetic patient with atypical pathogen.

Implications:

• Highlights Stenotrophomonas maltophilia as a potential, albeit rare, cause of skull-base osteomyelitis.
• Underscores the importance of advanced imaging (CT/MRI) in patients with mild otitis externa, particularly in immunocompromised or diabetic individuals.
• Suggests considering non-otogenic sources for SBO, including sinogenic, rhinogenic, pharyngogenic, or odontogenic infections.