Arthropathy in patients with CREST variant scleroderma

Background: Systemic sclerosis is a disease characterized by sclerosis of the skin, internal organs and vasculopathy. Articular manifestations are common, and include arthralgias, arthritis, and morning stiffness, which in some cases can be confused with rheumatoid arthritis (RA). Patients develop functional impairment and thickening of the skin including around the joints, with inflammation and fibrosis of tendon sheaths. However, articular inflammation is rare clinically, as is the development of articular erosions. Objective: To define the presence and characteristics of arthropathy in patients with scleroderma and distinguish it from RA. Methods: Case series of 106 Colombian patients with scleroderma evaluated between January 1998 and December 2004, of whom 5 had significant articular involvement and are the subject of this report. Results: All patients had the CREST variant of scleroderma. Their average age was 48.6 years (range 35-56). All had arthropathy affecting mainly the hands and feet. In the majority of cases the clinical picture resembled that of RA, with inflammation and subluxation of the metacarpophalangeal joints, and involvement of the feet with subluxation of the toes. Radiographs revealed joint space narrowing, subluxation, juxtaarticular osteopenia, carpal ankylosis and erosions. Rheumatoid factor was negative and antinuclear antibody (ANA) was positive with anticentromere antibodies in all patients. Conclusions: We conclude that there is a unique arthropathy of scleroderma which is due to inflammation and mechanical factors related to skin and periarticular involvement from the underlying disease. It is not due to coexisting RA. All of our cases had CREST variant scleroderma with erosive arthritis, negative rheumatoid factor, and positive ANA with centromere antibody. None fulfilled classification criteria for RA. This is a distinct subtype of scleroderma. Patients should be identified and treated promptly to avoid development of serious articular disease. The tendency to develop severe articular disease is likely immunogenetically linked.