[An update on Behçet's syndrome]

Behçet's syndrome (BS, synonym: Behçet's disease, or Adamantiades-Behçet's disease, ABD) is classified as a vasculitis of variable vessel size and can manifest itself in both arterial and venous vessels. Its extensive and at the same time interindividually very different clinical picture is not uncommon a challenge, both with regard to the diagnosis of this rheumatic systemic disease, which is rather rare in our latitudes, and its therapeutic options. In addition to the four cardinal symptoms of recurrent oral aphthae, genital aphthae, skin and eye lesions, the clinical picture offers numerous other manifestations which often require interdisciplinary cooperation. In addition to the above mentioned ocular involvement, which can still lead to blindness if inadequately treated, this is especially true for intestinal and cerebral manifestations as well as for large vessel vasculitis.A final revision of the European League Against Rheumatism recommendations for the management of Behcet's syndrome (EULAR) was made in 2018, and the recommendations are now established internationally as an important treatment guide. Therapy is based on the leading organ involvement. After adalimumab received approval for the treatment of posterior ocular involvement in 2016, another agent, apremilast, became available in 2020. The drug is recommended for the treatment of recurrent oral aphthae in adult Behçet's patients requiring systemic therapy. Nevertheless, there is a further need for new drugs.This article aims to highlight recent findings in the areas of epidemiology, immunopathogenesis & genetics, clinical findings, and therapy, with an emphasis on clinical relevance.