Systemic sclerosis sine scleroderma and limited cutaneous systemic sclerosis: similarities and differences.

OBJECTIVES: To compare a cohort of patients with systemic sclerosis sine scleroderma (ssSSc) vs. patients with limited cutaneous systemic sclerosis (lcSSc).

METHODS: Forty-five patients with ssSSc and 186 patients with lcSSc were investigated. Demographic, clinical and immunologic features and survival were compared.

RESULTS: There were no significant differences between ssSSc and lcSSc in gender, age at onset and interval between onset and diagnosis. ssSSc patients fulfilled the ACR criteria for SSc less than lcSSc patients (13%/77%, p<0.0001). There were no significant differences in articular involvement, myopathy, tendon friction rubs and gastrointestinal, pulmonary, cardiac and renal involvements. There was a trend to higher prevalence of pulmonary arterial hypertension (PAH) in ssSSc patients (29%/19%) but not reach significant difference. The prevalence of antinuclear and anticentromere antibodies and slow capilaroscopic pattern was similar. Sicca syndrome (13%/30%; p=0.024), digital ulcers (16%/50%; p<0.0001), calcinosis (11%/26%; p=0.047) and acroosteolysis (0% /10%; p=0.028) were more frequently in lcSSc. Survival at 5, 10, and 15 yr was not different in ssSSc and lcSSc patients (100%/98%, 100%/98%, and 92%/89%, respectively).

CONCLUSIONS: ssSSc and lcSSc patients share demographic, clinical and immunologic features. Survival is also similar in both groups. Differences are mainly due to peripheral vascular manifestations. However, despite great similarities, we believe that ssSSc patients should be considered as a different subset in order to avoid misdiagnosis. ssSSc patients should be truly differentiated from early SSc using sensitive and specific studies looking for any asymptomatic organ involvement.