Systemic sclerosis (SSc), formerly known as scleroderma, is a relatively uncommon connective tissue disorder characterized by fibrous and degenerative changes in the skin and other organ systems. The term scleroderma is often used for sclerosis affecting only the skin. SSc is further classified into limited and diffuse subtypes, depending mainly on the extent of skin involvement. The etiology of this disease is poorly understood but involves activation of fibroblasts that produce excessive collagen deposition, inflammation, and fibrosis. SSc is 4 times more common in women than in men, with age of onset typically in the third or fourth decade of life. African American individuals seem to be more prone to the diffuse form of the disease, although it can affect other groups as well. The limited form of SSc rarely involves internal organs and has a better prognosis, often with a normal life span. It is frequently associated with the CREST syndrome (calcinosis, Raynaud phenomenon, esophageal involvement, sclerodactyly, and telangiectasia).
Signs and Symptoms
The hallmark of SSc is changes to the skin, namely thickening, tightening, and induration, with subsequent loss of mobility and contracture (Fig 9-6). The disease usually begins peripherally, in the fingers and hands, and subsequently spreads centripetally up the arms to involve the face and body. Telangiectasia and calcinosis are common. Vascular effects also occur; more than 95% of SSc patients experience Raynaud phenomenon (see Fig 9-5). Less frequently, permanent damage to blood vessels can result in digital ulcers and ischemia.
Figure 9-6 Typical skin changes in systemic sclerosis. A, Thickening and tightening of the fingers. B, Associated ischemic changes in the peripheral digits.
(Used with permission from Wolff K, Johnson RA, Saavedra AP. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. 7th ed. www.accessmedicine.com.)
Organ involvement is present in more than 90% of patients; the most common is esophageal dysmotility with gastroesophageal reflux secondary to stricture formation and submucosal fibrosis. The small and large intestines may also be affected, with decreased motility, malabsorption, and diverticulosis. Cardiopulmonary disease is manifested primarily by pulmonary vascular fibrosis leading to restrictive lung disease and decreased diffusing capacity, pulmonary hypertension, and right-sided heart failure. These complications, along with arrhythmias arising from cardiac fibrosis, account for a cumulative 5-year survival rate around 75% from the time of diagnosis. Musculoskeletal characteristics include polyarthralgias, tendon friction rubs, and occasionally myositis. Renal disease is seen in approximately 50% of patients.
Excerpted from BCSC 2020-2021 series: Section 1 - Update on General Medicine. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.