Clinical profiling and management outcome of atypical skull base osteomyelitis

Background: Malignant otitis externa or skull base osteomyelitis arises as a complication of otological infection in immunocompromised individuals, especially elderly diabetics. With increasing awareness of the disease and better diagnostic modalities, there has been an increased reporting of atypical osteomyelitis of skull base (AOSB). Atypical osteomyelitis of skull base is a relatively rare yet an emerging clinical entity that also occurs in immunocompromised elderly individuals, however, in the absence of a pre-existing otological or rhinological infection. The purpose of this study was to review the clinical presentation and treatment protocol followed in patients diagnosed with atypical skull base osteomyelitis.Methods: A retrospective audit of medical records of patients diagnosed with AOSB between 2014 and 2018 was done. Clinical presentation and radiological assessment done prior to intervention was noted. All patients underwent transnasal endoscopic biopsy of tissue from clivus. Histopathological and microbiological profiling of biopsied tissue and treatment protocol followed was noted.Results: A total of 10 patients were included in the study out of which eight were male and two female. Eight patients were known diabetics and one patient had been on chronic oral steroid use. Majority presented with a vague dull aching headache and with one or more cranial nerve (CN) palsy(s). Radiological imaging showed clival involvement for all. All were managed conservatively with appropriate antibiotics. Disease resolution was defined as either complete resolution of symptoms and/or no residual lesion noted on follow-up MRI of skull base.Conclusions: Individuals presenting with non-specific symptoms of headache with CN palsy(s) with no obvious otological/rhinological infections, should raise suspicion of atypical skull base osteomyelitis. Histopathological diagnosis and microbiological assessment are an essential aid in conservative management with higher antibiotics. Patient compliance and long-term follow-up is essential for adequate and complete resolution of disease.