[Clinical Study of Skull Base Osteomyelitis].

Typical osteomyelitis is reportedly caused by Pseudomonous aeruginosa in elderly diabetic patients after malignant external otitis. Recently, complications have arisen due to the emergence of atypical osteomyelitis. We have experiensed 5 cases of skull base osteomyelitis at our hospital. All patients were male with a mean age of 75.2 years. Four patients had diabetes. Regarding the clinical and radiographic findings, patients 1, 2, and 3 had typical osteomyelitis after malignant external otitis, whereas patients 4 and 5 had atypical osteomyelitis without temporal bone findings. Sample culturing revealed Pseudomonas aeruginosa in 4 cases and Aspergillus in one. Intravenous antibiotics were administered to all patients. Two patients responded positively and survived, while 3 died. Typical osteomyelitis is reportedly caused by P. aeruginosa in elderly diabetic patients after malignant external otitis. Recently, complications have arisen due to the emergence of atypical osteomyelitis. The prognosis of skull base osteomyelitis is still poor in Japan. Early diagnosis and long-term antibiotic administration is required to improve outcome.