Objective: To determine the prevalence rate of primary Sjögren's syndrome (SS) in a community population of 2066 adults in a Beijing suburban village, and 100 inpatients, who were not necessarily admitted for rheumatic diseases.
Methods: Questionnaire and serological studies of antinuclear antibodies, rheumatoid factor, and anti-SSA, anti-SSB antibodies were done. Possible positive subjects were given eye and oral examinations for objective evidence of xerostomia and keratoconjunctivitis sicca.
Results: According to the Copenhagen criteria, the prevalence rate of primary Sjögren's syndrome in China was 0.77%, and it was 0.33% by modified San Diego criteria. In 100 inpatients, we found 4 cases of primary Sjögren's syndrome by Copenhagen criteria, and one case by modified San Diego criteria.
Conclusion: Primary Sjögren's syndrome is not a rare disease in China, but most cases are overlooked or misdiagnosed.