Systemic sclerosis (SSc), often called scleroderma, is a rare multisystem disease characterized by skin fibrosis, autoantibody production, and vascular abnormalities often leading to visceral disease. It can affect any organ system, particularly the gastrointestinal tract, kidney, heart, and lungs. Patients typically present with cutaneous sclerosis or Raynaud phenomenon (RP). The degree of skin involvement defines the clinical subset of the disease. Diffuse cutaneous SSc (dcSSc) involves the skin proximal to the neck, elbows, or knees, whereas involvement distal to these sites is known as limited cutaneous SSc (lcSSc); some authors include an intermediate group. Localized scleroderma, or morphea, is a different condition.
Elsevier, Treatment of Skin Disease (Fifth Edition) Comprehensive Therapeutic Strategies 2018, Pages 764-768