Scleroderma is a systemic disease of uncertain cause that is characterized by widespread collagen deposition that results in tissue fibrosis. Progressive systemic sclerosis, another term used to describe this disease entity, more aptly reflects the typical clinical course and multiorgan nature of scleroderma. Cutaneous involvement can be limited to the face and distal extremities, or it can be diffuse in nature. Limited skin disease is frequently associated with CREST (ie, calcinosis, Raynaud phenomenon, esophageal disease, sclerodactyly, and telangiectasia) syndrome. The prognosis for patients with diffuse cutaneous disease generally is worse because of frequent renal, cardiac, and pulmonary involvement. As the disease progresses, the skin gradually thickens, hardens, and becomes adherent to the underlying subcutaneous tissue, and this results in an appearance that has been labeled \"hide-bound\" to reflect the skin\'s superficial resemblance to skin of domestic animals such as cattle. This term was later adopted to describe analogous changes of atrophy and fibrosis in the bowel wall, as seen on barium studies

GIT - Gastrointestinal involvement manifests in up to 90% of patients with systemic sclerosis and represents a substantial cause of morbidity. The underlying pathologic changes, which are similar regardless of their location along the gastrointestinal tract, consist of smooth muscle atrophy and fibrosis caused by collagen deposition primarily in the tunica muscularis. Any portion of the gut may be affected, but esophageal disease typically predominates. There is esophageal disease involvement in 50%–90% of patients with scleroderma. The small bowel is the next most common sight of involvement; disease in this region is present in up to 50% of cases. Colonic and gastric findings are less frequent.

Systemic sclerosis involves the small bowel in up to 50% of cases. Hypomotility from smooth muscle atrophy and fibrosis, a common finding, leads to stasis, dilatation, and pseudo-obstruction. The radiographic appearance of small-bowel dilatation and air-fluid levels in patients with scleroderma can be cause for concern, and barium studies may be necessary to exclude mechanical obstruction. Similar small intestinal dilatation occurs with pseudo-obstruction from other causes—namely visceral myopathies and visceral neuropathies—and with celiac disease and true mechanical obstruction. However, because circular muscle involvement does not predominate, none of these conditions will demonstrate the hide-bound sign of valvular packing that is seen with scleroderma; thus, this sign is a useful discriminating finding. In one series of patients with scleroderma, Asymmetric smooth muscle atrophy and fibrosis of the inner circular layer of the tunica muscularis relative to the outer longitudinal layer probably account for the appearance of the hide-bound sign. Foreshortening of the bowel caused by longitudinal smooth muscle contraction results in packing of the valvulae conniventes, which is further accentuated by the associated dilatation of the affected loops. Horowitz and Meyers found that more than 60% of small-bowel studies demonstrated the hide-bound bowel sign, and the findings were most prominent in the jejunum and proximal ileum.

Additional gastrointestinal manifestations of scleroderma include delayed gastric emptying, megaduodenum, pneumatosis cystoides intestinalis, intestinal telangiectasia and bleeding, bacterial overgrowth, malabsorption, absent gastrocolic reflex, and constipation. In addition to the hide-bound sign, another characteristic barium study finding that also is related to smooth muscle fibrosis and atrophy is wide-mouthed intestinal diverticula, or sacculations.These sacculations can occur in the small bowel and esophagus, but they more commonly involve the colon, where they are accentuated on postevacuation radiographs.

MSK - Patients may present with generalized arthralgias and morning stiffness that may mimic other systemic autoimmune diseases. Clinically apparent synovitis is uncommon. Hand and joint function may decline over time because of skin tightening rather than arthropathy. Tendon friction rubs may be detected as the tendon is moved actively or passively, and friction rubs may precede joint involvement.

Acroosteolysis (ie, resorption or dissolution of the distal end of the phalanx) may occur. Flexion contractures of any affected joint may occur.