Systemic Sclerosis Sine Scleroderma: Distinct Features in a Large Brazilian Cohort

Objective: Systemic sclerosis sine scleroderma (ssSSc) is an infrequent SSc variant characterized by visceral and immunological manifestations of SSc in the absence of clinically detectable skin involvement. We sought to delineate the characteristics of ssSSc in a cohort of Brazilian patients and contrast them with those in the literature.

Methods: SSc patients seen at two academic medical centres in Brazil were retrospectively analysed. Patients were classified as ssSSc if they presented with RP, positive ANAs and at least one visceral involvement typical of SSc in the absence of skin thickening. Demographics, clinical and laboratory data were obtained by chart review. Literature review was performed by searching available original studies up until June 2012.

Results: Among the 947 consecutive patients with SSc, 79 (8.3%) were classified as ssSSc. Oesophagus was the most frequently affected organ (83.1%), followed by pulmonary involvement (63.2%). Compared with the limited cutaneous form of SSc, telangiectasia was the only variable significantly different after multivariate logistic regression analyses (odds ratio 0.46; 95% CI 0.27, 0.81). Compared with the diffuse cutaneous form of SSc, multivariate analyses revealed that ssSSc patients were less likely to be male (odds ratio 0.15; 95% CI 0.04, 0.57), have digital ulcers (odds ratio 0.26; 95% CI 0.13, 0.51) or anti-Scl70 antibodies (odds ratio 0.19; 95% CI 0.07, 0.55) and less frequently treated with CYC (odds ratio 0.23; 95% CI 0.12, 0.43). These features were comparable to those in the published literature.

Conclusion: In this series, patients with ssSSc had a relatively mild disease with good prognosis.