Behçet: the syndrome.

Behçet's syndrome (BS) is a systemic vasculitis characterized by a relapsing and remitting course. It can involve the skin, mucosa, joints, vessels (arteries and/or veins), eyes, and nervous and gastrointestinal systems, and so is referred to as a syndrome rather than as a unique and nosologically distinct condition. These involvements may present alone or co-exist in the same patient. Although all the possible combinations of the above-mentioned manifestations may occur, clusters of commonly co-existing involvements (also referred to as 'disease phenotypes') have been suggested, namely 'mucocutaneous and articular', 'peripheral vascular and extra-parenchymal neurological' and 'parenchymal neurological and ocular' phenotypes have been described. Patient-specific demographic and genetic features have been described as positively or negatively associated with specific disease phenotypes. This review will focus on the different clinical features of Behçet's syndrome, summarizing current evidence on the distinct disease manifestations as well as the major phenotypes.