Juvenile-onset Behçet's syndrome and mimics.

Behçet's syndrome (BS) presents in childhood in up to 20% of reported cases. Diagnosis is clinical and multiple classification criteria have been developed. Presentation is heterogenous with recurrent oral ulceration often being the presenting feature. Mucocutaneous disease including genital ulceration and skin involvement is a common phenotype. Vascular and neurological manifestations are rarer, particularly in childhood. Musculoskeletal and gastro-intestinal involvement which do not form part of commonly used classification criteria, appear more frequent in children. Treatment approaches are extrapolated from studies of adult onset disease. The pathogenesis of BS is not well defined although dysregulation in both innate and adaptive immune systems, together with abnormal antigen presentation have been described. The recent discovery of monogenic mimics of BS requires further genetic studies to understand the burden of monogenic autoinflammatory conditions affecting those with a BS phenotype.