Malignant (Necrotizing) Otitis Externa

Abstract

Malignant or necrotizing otitis externa is a rare, invasive infection that begins in the external ear canal and spreads to adjacent tissue. Severe infection may extend to the base of the skull or intra-cranially. Medical knowledge of malignant otitis externa is primarily derived from retrospective case series. The majority of reported patients are elderly diabetics infected with Pseudomonas aeruginosa. Patients typically present with otalgia and otorrhea with little evidence of systemic illness. Diagnosis is based on clinical presentation, radiographic imaging with CT or MRI, and tissue histology and culture. Treatment requires prolonged systemic antibiotics and surgery is not required for cure in most cases. Mortality for malignant otitis externa has improved since the disease was first characterized, but a significant number of patients have recurrent disease and require multiple courses of antibiotics. Clinicians should suspect malignant otitis externa in diabetic patients who present with symptoms of otitis externa.