Necrotizing Otitis Externa: A Disease Barely Known to Neurosurgeons

ABSTRACT

Necrotizing otitis externa (NOE), also known as malignant otitis externa (MOE), is a severe and rare infectious disease of the external auditory canal (EAC). Without treatment, it may progress to skull base involvement. The bacteria Pseudomonas aeruginosa is the most common causative agent (90% of the cases), and affects immunocompromised subjects, particularly diabetic patients. Severe chronic otalgia, otorrhea, and cranial nerve palsy are the most common clinical presentations. Patients with NOE are frequently referred to neurosurgery because of the neurological impairment and skull base compromise. The definitive diagnosis is frequently elusive, requiring a high index of suspicion. Several laboratorial tests, imaging modalities, and the histologic exclusion of malignancy may be required. An early diagnosis and aggressive treatment reduce morbidity and mortality. We present four NOE cases to illustrate the spectrum of clinical presentation and complementary exams. According to the literature, more effort for early diagnosis and treatment is required, and neurosurgeons play an important role in this task.