[Cogan syndrome: sudden, bilateral high-grade hearing loss].

We report 2 cases of Cogan's syndrome. One female patient had a typical interstitial keratitis and bilateral hearing impairment, the other had dramatically progressive deafness, combined with failure of the left vestibule and severe conjunctivitis resistant to treatment and otitis externa. The typical Cogan's syndrome with interstitial keratitis developed only a few weeks later. The disease is caused by an auto-immune response. The hearing impairment is mainly due to endolymphatic hydrops. Corticosteroids are the treatment of choice.