Systemic sclerosis: To subset or not to subset, that is the question

Abstract

Systemic sclerosis (SSc) is a heterogeneous disease with variability in autoantibody profiles, skin andinternal organ involvement, disease trajectory, and survival. The ability to identify more homogeneoussubsets of SSc patients has informed patient care and been an essential aspect of SSc research.In this article, the historic evolution of subsetting systems in SSc are described including clinicallybased SSc subsetting systems, their utility, strengths, and limitations. There is a shifting paradigm ofSSc subsets, including biologic classification of SSc subsets and fully data-driven approaches to SScsubset classification, taking into consideration the needs of the SSc global community in the modernera and the ability to prognosticate patients with SSc.