Malignant Otitis Externa (Skull Base Osteomyelitis)

Abstract

It is recognized that malignant otitis externa is refractory to treatment and invasive otitis externa caused by pseudomonas aeruginosa and is often seen in immunocompromised elderly patients. Because inflammation deriving from temporal bone spreads to surrounding tissues along the skull base and may cause cranial nerve palsy, it has also been called skull base osteomyelitis (SBO).

Most SBO patients present with severe headache, however, levels of C-reactive protein, a marker of inflammatory reaction, are often low. The most important aspect in the diagnosis of SBO is to consider the differential diagnosis of malignant tumors, tuberculosis otitis media, and otitis media with ANCA-associated vasculitis. Diagnostic imaging of SBO is marked by cortical bone destruction in CT and the low intensity of bone marrow in T1 weighted-images of MRI. Standard treatment of SBO is intravenous administration of antibiotics for 6 to 8 weeks. Additional long-term antibiotic therapy may also be recommended. Because SBO often occurs in elderly patients, it is important to consider the general condition of the patient and the deterioration of daily life activities and cognitive function. Therefore, the collaboration of medical professionals such as pharmacists, nurses, physical therapists, and medical social workers is also necessary.