Undifferentiated connective tissue disease - an unsolved problem:revision of literature and case studies.

In clinical practice, patients with a range of signs and symptoms suggestive of connective tissue disease, but who do not fulfil the classification criteria for a defined disease are often found. This condition is defined as, Undifferentiated Connective Tissue Disease (UCTD). Most of the authors consider UCTD as a distinct clinical entity, generally stable during follow-up. Despite this, no mutual agreement regarding criteria for its diagnosis has been reached. The clinical, serological, therapeutical and evolutional patterns of 41 patients initially diagnosed as having early UCTD during a 3-year followup are described in this study. At the end of the observational period, 21 percent of the enrolled patients, followed throughout the follow-up, demonstrated clinical evolution to a defined connective tissue disease (CTD), whereas 52 percent of the observed subjects maintained an undifferentiated profile with variable clinical findings and presenting a generally stable disease over time. The remaining patients showed clinical improvement or complete regression of the symptoms associated with normalization of the inflammatory indexes. The role of therapy in these different clinical courses is discussed.