Synopsis at a Glance
- Systemic sclerosis (SSc) is a multisystemic disease, characterized by excessive fibrosis, inflammation, and vasculopathy.
- The pathogenesis of this autoimmune process remains unclear.
- Differential diagnosis of SSc includes severe forms of localized scleroderma as well as many other scleroderma-like conditions.
- Patients with SSc are classified into two major subtypes depending on the extent of skin sclerosis [diffuse systemic sclerosis (dSSc) and limited systemic sclerosis (lSSc)]. Patients with an overlap syndrome, are characterized by additional clinical features of other rheumatic diseases.
- Raynaud phenomenon (RP) and skin sclerosis are almost always present.
- SSc is defined by sclerotic/fibrotic alterations of the skin and internal organs (digestive tract, lung, kidney, and heart), which can lead to severe dysfunction of almost any visceral organ.
- The heterogeneity and clinical course of SSc requires the urgent need of interdisciplinary collaborations and regular, at least yearly, follow-up visits.
- Although the disease is still not curable, there have been substantial advances in therapy for organ-based complications of SSc.
Systemic sclerosis (SSc) is a rare, multisystem disease, based on autoimmunological processes, vascular endothelial cell injury and an extensive activation of fibroblasts. It is characterized by a large individual variability in the extent of skin and organ involvement, as well as in disease progression and prognosis. The skin, esophagus, lung, heart and kidneys are the most frequently affected organs.
Women are more frequently affected by SSc, with a female-to-male ratio between 3:1 up to 14:1.1–4 The age of disease onset ranges between 30 and 50 years.4 However, male patients have earlier onset than female patients. Blacks with SSc are frequently younger than whites. Published data about incidence rates increased from 0.6 to 16 patients per million inhabitants, which is also true for the prevalence rates, which rose from 2 to 233 patients per million inhabitants per year,1–3,5 depending on methodological differences in case definition and ascertainment as well as the investigated time period.
SSc has the highest case-specific mortality of any of the autoimmune rheumatic diseases, but it varies individually depending on racial or ethnic differences, presence and severity of organ involvement, SSc subsets, age at diagnosis and gender differences. Although not curable, there have been substantial advances in treatment options for organ-based complications of SSc.
The pathogenesis of this complex disease involves multiple cell types (endothelial cells, epithelial cells, fibroblasts, and lymphocytic cells) interacting through a variety of mechanisms that are dependent on their microenvironment and key mediators.
Major facets of the disease include inflammation, vasculature, and connective tissue-producing cells. The clinical heterogeneity of SSc makes it likely that distinct pathogenetic mechanisms predominate in particular patients or subsets of disease. Similarly, it is likely that the mechanisms are not the same at different stages of SSc. Although a genetic component to etiopathogenesis is likely and evidence supports genetic factors in severity and susceptibility, there is also strong ...