SCLERODERMA (PROGRESSIVE SYSTEMIC SCLEROSIS)
Scleroderma, or progressive systemic sclerosis, is an idiopathic, life-threatening connective tissue disease that involves many organ systems. There is often an insidious onset of diffuse skin thickening, sclerodactyly, Raynaud’s phenomenon, capillary nail fold loops, and tightening of the skin around the orifice of the mouth. As the name implies, this is a progressive disease with significant morbidity and mortality.
Clinical Findings: Progressive systemic sclerosis is an unrelenting connective tissue disease that predominantly affects young adult women. African Americans appear to be slightly more affected than Caucasians. It occurs across all ethnic backgrounds. Skin findings are variable from patient to patient, but all have a persistent and relentless sclerosis of the skin. It begins insidiously, and slowly the skin begins to thicken and harden, causing the underlying dermis to become firm to palpation. The progressive sclerosis causes digital tip ulceration as the peripheral distal blood vessels begin to thrombose. The hair shafts in the affected skin disappear at a slow and steady, almost unnoticeable rate. This is caused by crowding out of the hair follicles by the excessive production of dermal collagen.
As the dermal sclerosis progresses, skin tightness is noticed, and the patient may become aware of difficulty with movement of the fingers. The tightness around the mouth is manifested by an increase in the furrowing circumventing the oral orifice and inability to open the mouth as wide as was once possible. Patients may lose the ability to make facial expressions as the skin tightens and hardens in place. Patients may be left in an expressionless state.
The skin overlying the sclerosis develops hyperpigmentation and hypopigmentation; this has been given the name “salt-and-pepper discoloration.” The capillary loops around the nail folds become enlarged and engorged and are visible without magnification. These dilated capillary loops occur in up to three quarters of all patients with progressive systemic sclerosis.
Sclerodactyly is the term given to the progressive thickness and associated tightness of the digits. It is caused by the overabundance of collagen production within the dermis.
Progressive systemic sclerosis is a multisystem dis- order that not only affects the skin but also causes significant, life-threatening damage to internal organs. The esophagus is affected early, and patients complain of dysphagia and an inability to swallow food easily. Aspiration of food and liquids is common and often leads to aspiration pneumonia. Pulmonary fibrosis is a leading cause of morbidity and mortality. Patients complain of shortness of breath and a cough. Pulmonary hypertension is almost universally seen. Conduction defects can develop in the cardiovascular system, and thickening of the myocardial wall may cause a constrictive cardiomyopathy. The kidneys are also involved, and a subset of patients develop renal failure and hypertension.
Pathogenesis: The initiating factor that causes the fibroblast to make ever-increasing amounts of collagen in an unregulated manner is unknown. Many possible targets are being explored as potential causes of progressive systemic sclerosis, including fibroblasts, endothelial cells, various environmental antigens, and internal defects within T cells.
Histology: The histological findings in the skin are characteristic. Punch biopsy specimens are very square on gross evaluation because of the increased amount of dermal collagen. Microscopic evaluation shows an increased amount of collagen that replaces everything including the adnexal structures and subcutaneous fat. The extensive collagen is so vast that it can appear as an amorphous eosinophilic mass with nothing between the collagen bundles. A sparse inflammatory infiltrate is present at the interface of the collagen and underlying remaining tissue. Plasma cells may be prominent.
Treatment: Treatment for this skin disease is difficult. Pruritus can be controlled with antihistamines and topical corticosteroids. Ultraviolet phototherapy has been used. The deeper-penetrating ultraviolet A (UVA) rays work best. This is often administered in the form of psoralen + UVA (PUVA) therapy. Systemic corticosteroids and nonsteroidal immunosuppressant therapy are the main treatment strategies for this disease. Progressive systemic sclerosis requires a multidisciplinary approach to achieve the best therapeutic results.