French protocol for diagnosis and management of Cogan's syndrome.

Cogan's syndrome is a condition of unknown origin, classified as a systemic vasculitis. It is characterised by a predilection for the cornea and the inner ear. It mainly affects Caucasian individuals with a sex-ratio close to one. Ophthalmological and cochleo-vestibular involvement are the most common manifestations of the disease. The most frequent ophthalmological type of involvement is non-syphilitic interstitial keratitis. Cochleo-vestibular manifestations are similar to those of Meniere's syndrome. The disease progresses in ocular and ear-nose-throat (ENT) flares, which may occur simultaneously or in isolation. Association with other autoimmune diseases, particularly other forms of vasculitis such as polyarteritis nodosa or Takayasu's arteritis, is possible. Ocular involvement, as well as cochleo-vestibular involvement, can be inaugural and initially isolated. Onset is often abrupt. The characteristic involvement is "non-syphilitic" interstitial keratitis. It is usually bilateral from the outset or becomes so during the course of the disease. It presents as a red, painful eye, possibly associated with decreased visual acuity. Cochleo-vestibular involvement is usually bilateral from the outset. It is characterised by the sudden onset of continuous rotational vertigo associated with tinnitus, rapidly progressive sensorineural deafness. Approximately 30-70% of patients present with systemic manifestations. Deterioration in general status with fever may be present. Laboratory evidence of inflammatory syndrome is associated in 75% of cases. Cogan's syndrome is a presumed autoimmune type of vasculitis, although no specific autoantibodies have been identified. Ocular involvement is usually associated with a good prognosis, with total visual acuity recovery in the majority of cases. In contrast, cochleo-vestibular involvement can be severe and irreversible. Therapeutic management of Cogan's syndrome, given its rarity, lacks consensus since no prospective randomised studies have been conducted to date. Corticosteroid therapy is the first-line treatment. Combination with anti-TNF therapy should be promptly discussed.