Undifferentiated Connective Tissue Disease (UCTD)
The term UCTD refers to unclassifiable systemic autoimmune diseases that share clinical and serological manifestations with definite connective tissue diseases (CTDs) but not fulfill any of the existing classification criteria. In UCTD, symptoms and autoimmune features are generally milder than in definite CTDs, however major clinical manifestations or objective signs leading to a formal diagnosis of a definite systemic autoimmune disease may later appear in a subset of patients. In others a rather benign, yet disturbing, picture may remain stable for longer. These patients usually fall within the proposed preliminary classification criteria for UCTD that include at least one clinical manifestation of CTDs, positive ANA results, and disease duration of at least three years. In this condition, major organ involvement (such as renal or neurologic) is usually absent, while very frequent symptoms include Raynaudís phenomenon, arthralgias, sicca symptoms, mild haematological abnormalities, alopecia, skin rashes. As such, the therapeutical intervention in UCTD is usually milder than in definite CTD, yet persons suffering from UCTD necessitate a clinical and serological follow-up to individuate the evolution toward a definite CTD or the appraisal of major autoimmune complications requiring more aggressive therapy.