ESSENTIALS OF DIAGNOSIS
Limited disease (CREST syndrome): skin thickening confined to face, neck, and distal extremities.
Diffuse disease (20%): widespread thickening of skin, including truncal involvement, with areas of increased pigmentation and depigmentation.
Raynaud phenomenon and antinuclear antibodies are present in virtually all patients.
Systemic features: gastroesophageal reflux, gastrointestinal hypomotility, pulmonary fibrosis, pulmonary hypertension, renal involvement.
Systemic sclerosis (scleroderma) is a rare chronic disorder characterized by diffuse fibrosis of the skin and internal organs. The causes of systemic sclerosis are not known, but autoimmunity, endothelial cell damage, and increased production of extracellular matrix appear to play key pathogenic roles. Symptoms usually appear in the third to fifth decades, and women are affected two to three times as frequently as men.
Two forms of systemic sclerosis are generally recognized: limited (80% of patients) and diffuse (20%). In limited systemic sclerosis, which often has one or more features of the CREST syndrome (representing calcinosis cutis (see eFigure 20–21), Raynaud phenomenon (see eFigure 20–22), esophageal motility disorder, sclerodactyly (eFigure 20–23), and telangiectasia), the hardening of the skin (scleroderma) is limited to the face, neck, and skin distal to the elbows and knees. In contrast, in diffuse systemic sclerosis, the skin changes also involve the trunk and proximal extremities. Tendon friction rubs over the forearms and shins occur uniquely (but not universally) in diffuse systemic sclerosis. In general, patients with limited systemic sclerosis have better outcomes than those with diffuse disease, largely because life-threatening lung or kidney disease is rare. Cardiac disease is also more characteristic of diffuse systemic sclerosis. Patients with limited disease, however, are more susceptible to digital ischemia, leading to finger loss, and to life-threatening pulmonary hypertension. Small and large bowel hypomotility, which may occur in either form of systemic sclerosis, can cause constipation alternating with diarrhea, malabsorption due to bacterial overgrowth, pseudoobstruction, and severe bowel distention with rupture.
Sclerodactyly of the hands in a patient with systemic sclerosis. (Used, with permission, from Nicole Richman, MD.)
Raynaud phenomenon is usually the initial manifestation and can precede other signs and symptoms by years in cases of limited systemic sclerosis. Polyarthralgia, weight loss, and malaise are common early features of diffuse systemic sclerosis but are infrequent in limited disease. Cutaneous disease usually, but not always, develops before visceral involvement and can manifest initially as non-pitting subcutaneous edema associated with pruritus. With time the skin becomes thickened and hidebound, with loss of normal folds. Telangiectasia (eFigure 20–24), pigmentation, and depigmentation are characteristic. Ulceration of the fingertips and subcutaneous calcification are seen. Dysphagia and symptoms of reflux due to esophageal dysfunction are common and result from abnormalities in motility and later from fibrosis. Fibrosis and atrophy of the gastrointestinal ...