Beware of covert enemies: malignant otitis externa with base of the skull osteomyelitis, a case report and review of literature.

Background: Malignant otitis externa (MOE) is a serious infection of the external auditory canal that is frequently associated with skull base osteomyelitis (SBO) as well as secondary neurological sequelae. Patients with poorly controlled diabetes mellitus or immunosuppression are at increased risk of developing such critical infection for multiple local and systemic factors. While most cases are secondary to bacterial infections particularly, fungal infections are also occasionally encountered, often associated with delayed diagnosis and high morbidity and mortality.

Case Report: We report a case of a 63 years old man with uncontrolled diabetes mellitus who presented with symptoms and signs of MOE, supported by radiological assessments. The patient was treated presumptively with a prolonged course of antibiotics without clinical improvement, coupled with progression of radiological findings and significant disease extension. Reassessment with biopsies and tissue cultures from external auditory meatus, tempo-mandibular bone, as well as base of the skull grew . The patient received induction treatment with high dose liposomal amphotericin followed by fluconazole to control disease progression and complications.

Conclusion: MOE with secondary skull base osteomyelitis is rare and difficult to diagnose with no clear guidance on assessment and management. Clinicians should be aware of the unusual presentations where microbiological and histopathological evaluations are essential for proper management.