Abstract
Skull base osteomyelitis (SBO) is a rare but potentially life-threatening serious infection. It is most often caused by Pseudomonas aeruginosa and typically affects elderly people with diabetes or weakened immune systems. We present an 80-year-old man with diabetes who was diagnosed with SBO with left facial nerve involvement after initial misdiagnosis and inadequate response to treatment for otitis externa and Bell's palsy. Imaging and transmastoid biopsy confirmed the diagnosis. Although prolonged antibiotic therapy suppressed the infection, the left facial nerve palsy remained unresolved. This case highlights the diagnostic challenges, the need for early imaging and biopsy, and the importance of tailored treatment and long-term follow-up to prevent irreversible complications.