Scleroderma, Raynaud’s Phenomenon, and Related Conditions

The clinical differential diagnosis of “hard skin” can be divided into two main diagnostic categories: morphea and morphea-like conditions and systemic sclerosis and sclerodermoid conditions. Patients with morphea and morphea-like conditions tend to have more asymmetric, discontinuous skin involvement, while patients with systemic sclerosis and sclerodermoid conditions tend to have more symmetric, distal, and continuous skin involvement. Although morphea and systemic sclerosis share a common endpoint of “hard skin” with a histologic correlate of cutaneous sclerosis, differences in pathophysiology suggest they are distinct disease processes rather than a disease spectrum. Further, while morphea tends to be localized to the skin and structures directly underlying, systemic sclerosis demonstrates the highest disease-related mortality of any autoimmune connective tissue disease due to visceral involvement (e.g., interstitial lung disease and pulmonary arterial hypertension). From a practical standpoint, the presence of sclerodactyly, nailfold capillary changes, and Raynaud's phenomenon are useful in distinguishing systemic sclerosis and its attendant complications from other causes of hard skin.