Recent epidemiological work suggests that genetic background overrides environmental factors in the pathogenesis of Behcet's syndrome (BS). There are at least two clusters of disease expression. The first is the cluster of superficial vein thrombosis, deep vein thrombosis and dural sinus thrombi; the second cluster is that of acne, arthritis and enthesitis. The association of antibodies to anti-Saccharomyces cerevisiae antibodies and the presence of inflammatory bowel disease is perhaps another such cluster. The presence of such clusters suggests that there might be more than one disease mechanism operative in this complex disorder. There is a recent trend to classify BS with the autoinflammatory disorders. However, practically all autoinflammatory conditions are recurrent fever syndromes of children, and are genetically linked to well-defined loci; none of this is true for BS. Recent guidelines from the European League Against Rheumatism are quite useful for the management of the disease in organ systems other than the vascular, neurological and gastrointestinal systems, because of the lack of controlled studies related to these latter pathologies.