The relevance of the extent of skin sclerosis and of other clinicoserological features in diagnosis, severity and prognosis of disease was studied in a large number of unselected patients with systemic sclerosis (SSc). One hundred and fifty-one patients with SSc (126 F and 25 M, mean age 48 +/- 14 SD) followed for 5.3 +/- 3.2 years were included. Patients were divided into 3 cutaneous subsets: limited (68), intermediate (46) and diffuse SSc (37). Serological markers were detected in 288 patients with Raynaud's phenomenon and other connective tissue diseases (CTD). Limited and intermediate SSC prevailed in female patients while the diffuse subset was more frequent in males (p less than 0.0001). Duration of Raynaud's phenomenon before disease onset was shorter in the diffuse variant (p less than 0.0001). A wider cutaneous involvement was associated with more severe forms of SSc. Diffuse subset showed the poorest prognosis at 10 years of followup compared with intermediate (p less than 0.05) and limited variant (p less than 0.001). Intermediate SSc seems a distinct variant of SSc on the basis of clinical manifestations and survival. Among serological markers, anticentromere, anti-Scl-70 and antinucleolar antibodies were found in 21, 40 and 27% of the cases, respectively; these were statistically less frequent (p less than 0.0001) in other CTD. In 83.5% of patients with SSc at least one of these specific markers was recorded. Anticentromere antibodies were correlated to sex (female), limited SSc, calcinosis and telangiectasia. On the contrary anti-Scl-70 was associated with diffuse and intermediate subsets and with more severe SSc manifestations.(ABSTRACT TRUNCATED AT 250 WORDS)