Atypical Manifestation of Skull Base Osteomyelitis Secondary to Malignant Otitis Externa Following Radiotherapy: A Case Report.

Skull base osteomyelitis represents a rare but potentially fatal complication of malignant otitis externa (MOE), predominantly affecting elderly patients with diabetes or immunosuppression, and may also occur in individuals with a history of head and neck radiotherapy. We report the case of a 79-year-old female with poorly controlled diabetes and a remote history of undifferentiated carcinoma of the nasopharynx (UCNT) treated with radiotherapy 17 years prior, who neglected chronic, fluctuating otalgia. She presented with massive left-sided otorrhagia complicated by hemorrhagic shock and a left peripheral facial palsy graded House-Brackmann IV. High-resolution imaging demonstrated extensive destruction of the temporal bone and skull base, and microbiological cultures identified Pseudomonas aeruginosa. Prompt, prolonged targeted antibiotics led to complete clinical recovery. This case underscores the critical importance of early recognition, meticulous longitudinal follow-up of post-radiotherapy patients, and aggressive multidisciplinary management to prevent potentially life-threatening complications. The unusual presentation of this case makes it worthy of sharing.