[Cogan's syndrome: a diagnostic challenge].

Classical Cogan's syndrome is a disease of the inner ear with participation of the eyes, typically involving keratitis. If no objectively assessable optical symptoms are present, a diagnosis is difficult. Additional nonspecific symptoms can, combined with inner ear participation, suggest Cogan's syndrome. Between 2001 and 2003, we documented the course of two patients with Cogan's syndrome. As indicated in the literature, organ related symptoms could be related to a generalized vascular illness. In addition to the usual otological symptoms with cochleovestibular dysfunction and symptoms of typical and atypical ocular manifestations, other non-specific changes were found. Interstitial keratitis was diagnosed in one patient while in the second objective ophthalmological symptoms failed. The symptoms could be improved by systemic and local administration of corticosteroids and immunosuppressive therapy, however, progression of inner ear deafness could not be stopped in one patient and a cochlear implant was necessary.