External Ear Disease: Keratinaceous Lesions of the External Auditory Canal.

Keratosis obturans (KO) and external auditory canal cholesteatoma (EACC) are two distinct keratinaceous lesions of the external ear. This article reviews the signs, symptoms, pathophysiology, workup, and treatment of each. Patients with either pathology can often be managed in the clinic with debridement; however, EACC is more likely to involve osteonecrosis and require more extensive operative management if disease is not confined to the canal on account of the bony erosion characteristic of cholesteatoma. If required for extensive disease, surgical approaches to both pathologies are similar.