Systematic review of ethnic variation in the phenotype of Behcet's disease

Objective: To systematically review the strength of evidence that supports the premise that there are different expressions in the clinical phenotype of Behcet's disease (BD) in different ethnic groups. Methods: The hierarchy of evidence and inclusion criteria were decided prior to the search for relevant literature. We searched Medline and Embase databases between 1966 and March 2005 for publications related to epidemiology of Behcet's disease or syndrome. Relevant papers were extracted in hard copy and the references of all these papers were then hand searched for further articles. Results: Four population-based studies, of which two were from Turkey, and seven non-population-based comparative studies were found. The majority of literature identified were case series and were not included in the review. There were insufficient cross-sectional studies from different populations to be able to compare phenotypic differences. None of the comparative studies found evidence of a difference in the clinical expression of BD between ethnic groups. Conclusions: There is insufficient evidence to support the premise that there are different expressions in the clinical phenotype of BD in different ethnic groups. Population-based, cross-sectional surveys or case-control studies using standardized criteria and clear ethnic definitions are suggested to investigate this hypothesis further.