Immunological Model and Otological Manifestations of Behçet's Disease

Abstract

Behcet's disease (BD) is an autoimmune vasculitis of unknown aetiology that is characterised by relapsing episodes of oral aphthous ulcers, genital ulcers, ocular lesions, skin lesions, and other manifestations, including vascular, gastrointestinal and neurological involvement. Behcet's disease exists worldwide, although there are significant regional differences, with the highest number of incidences in the Mediterranean, Middle East, and Far East. Behcet's disease occurs mainly between 18 and 40 years of age, and the male-to-female ratio is 7:1. The cause of Behcet's disease is unknown. It is believed to be due to an autoimmune process triggered by an infectious or environmental agent (possibly local to a geographic region) in a genetically predisposed individual. T cell homeostasis perturbation, especially Th1 and Th17 expansions and decrease regulation by Tregs are now supposed to be the cornerstone of BD pathogenesis. Inflammatory cytokine such as IL21 plays a critical role in pathogenesis of BD. Inner ear involvement in Behcet's disease was first reported by Alajouanine in 1961. Thereafter, many cases of inner ear involvement were described by other authors. The otological features of Behcet's disease can be divided into hearing loss and disequilibrium. The incidence of hearing loss in Behcet's disease has been reported to be 12 to 80% in several studies in the literature. Recently, some authors observed a significant percentage (59.2%) of hearing loss associated with Behcet's disease. According to other studies, hearing loss can be the fourth or even the third most common manifestation of the disease. The treatment of inner ear lesions remains unsatisfactory and is based on immunosuppressive agents and will not be reviewed here. This review focuses on the etiophatogenesis and otological manifestations of Behcet's disease and specifies the role of the otorhinolaryngologist as an integral member of the multidisciplinary team for clinical management of these patients.