dcSSc

Diffuse cutaneous systemic sclerosis (dcSSc) is a subset of systemic sclerosis characterized by rapid and widespread skin thickening that typically involves the trunk and proximal limbs within the first year of disease. It is a complex autoimmune connective tissue disorder marked by vasculopathy and progressive fibrosis, and it often features early internal organ involvement.

Clinically, dcSSc shows thickened skin proximal to the elbows and knees and on the trunk. Patients frequently develop Raynaud’s phenomenon, digital ulcers, and teleangiectasias. Internally, there is a high risk of interstitial lung disease, esophageal dysmotility, and scleroderma renal crisis. Autoantibodies such as anti-Scl-70 (topoisomerase I) and anti-RNA polymerase III are commonly associated with the diffuse form.

Diagnosis relies on the pattern of skin involvement, duration, and serology, supported by imaging and functional tests. The criteria consider new-onset diffuse skin thickening and autoantibody profile. Nailfold capillaroscopy and high-resolution CT for lung involvement help assess disease extent.

Pathophysiology involves immune activation, endothelial injury, and fibroblast-driven collagen deposition leading to fibrosis. Microvascular damage underlies many vascular manifestations. The disease course is variable; diffuse involvement generally progresses more rapidly and carries a higher risk of early organ complications than limited cutaneous disease.

Management is multidisciplinary and aims to minimize organ damage and improve function. Immunosuppressive therapies such as cyclophosphamide or mycophenolate mofetil may be used for skin and lung disease; nintedanib is approved for systemic sclerosis–associated ILD. Other measures include ACE inhibitors for renal crisis, vasodilators for Raynaud’s, and supportive care.