Systemic Sclerosis

Abstract

Systemic sclerosis (SSc) is an autoimmune systemic disease characterized by autoimmune reactivity (autoreactive B and T cells), which induces endothelial cell and fibroblast activation as well as overproduction of collagen leading to diffuse vascular pathology and widespread collagen accumulation. The vascular pathology is expressed by Raynaud’s phenomenon (RP), telangiectasias, ischemic digital ulcers, and pulmonary arterial hypertension (PAH). SSc can have three distinct clinical presentations: (a) limited cutaneous systemic sclerosis characterized by skin thickening on the face, neck, and distal aspects of the extremities, long-standing RP, esophageal hypomotility, anti-centromere antibodies, and a tendency for developing PAH; (b) diffuse cutaneous systemic sclerosis characterized by extensive and rapidly progressive skin thickening, acute development of RP and arthritis, presence of anti-topoisomerase I and anti-RNA polymerase III antibodies, a higher risk for interstitial lung disease, and scleroderma renal crisis development; and (c) systemic sclerosis sine scleroderma which refers to patients who develop internal organ involvement without skin involvement. Scleroderma can also present as a localized disease type which involves only the skin, and then it is termed morphea (single or multiple painless, discolored patches of the skin) or linear scleroderma (bands of skin thickening affecting a unilateral limb or the scalp and face, which may extend deeper into fascia, muscle, and bone and cause tissue atrophy). Diffuse fasciitis with eosinophilia, scleredema, and scleromyxedema are some of the scleroderma mimickers, and differential diagnosis can be challenging especially early in the disease course.