Scleromyositis - The new frontier.

In this review, we examine the clinical, serological, and pathological characteristics of muscle involvement in systemic sclerosis (SSc) and delineate features that distinguish it from other autoimmune myositis (AIM). We posit that muscle involvement in SSc represents a primary disease manifestation rather than an overlap between two conditions, reflecting shared pathogenic mechanisms with other organ manifestations in SSc. On this basis, we propose the term scleromyositis (SM). We further propose a conceptual framework for the pathogenesis of SM, review current knowledge on its prognosis and management, and present illustrative cases that highlight features that are unique to this entity. We aim to increase awareness of this under-recognized entity, highlight its broad spectrum and encourage a more consistent use of the term scleromyositis.