Sjogren's syndrome: clinical spectrum and current diagnostic controversies.

Although we have had a useful and internationally agreed-upon definition of Sjögren's syndrome (SS) for more than 30 years, we have not yet agreed upon criteria for diagnosing it. Understanding the clinical spectrum of SS and the various tests used to diagnose its components provides a basis for discussing controversies about diagnostic criteria. A review of the clinical features of SS and their diagnostic tests is followed by assessments of seven sets of diagnostic criteria and a proposal for future criteria. The various existing criteria use different combinations of clinical features and tests, which results in populations of different sizes and homogeneities being given the diagnosis of SS. Some criteria propose alternative tests in diagnosing components of SS, while others do not. Internationally accepted diagnostic criteria for SS that are as disease-specific as possible are needed for us to learn the epidemiology, pathogenesis, treatment, and prognosis of this clinically and scientifically important disease.