Systemic sclerosis Limited cutaneous * Distal sclerosis (most prominent in the fingers) * CREST syndrome * Complications: Pulmonary hypertension (most common pulm complication of limited/CREST) * Serology: Anticentromere Diffuse cutaneous * Proximal sclerosis (involves the trunk & proximal extremities) * Complications: Interstitial lung disease (most common pulm complication of diffuse), Scleroderma renal crisis * Serology: Anti–Scl-70 (anti–topoisomerase type I) Definitions & Notes * CREST = Calcinosis, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly & Telangiectasia. * SS is an autoimmune disease characterized by widespread fibrosis of multiple organ systems. * Early symptoms: Swelling of the fingers and mild pruritus. * Biopsy: Dermal layer expansion due to diffuse deposition of collagen (eosinophilic connective tissue), resulting in atrophy of the intradermal adipose tissue and dermal appendages (ie, hair follicles, glands). * Up to 80% of patients with SS develop pulmonary complications. Pulmonary Details * Interstitial lung disease is the most common pulmonary complication of diffuse cutaneous SS (ie, skin involvement extending proximal to the wrist that may affect the trunk). * Pulmonary hypertension is the most common pulmonary complication of limited cutaneous SS (ie, skin involvement is mainly in the hands and/or face), which is often associated with CREST syndrome.