Scleroderma overlap syndromes

Scleroderma is a connective tissue disease that causes fibrosis and vascular abnormalities, but that also has an autoimmune component. Many patients with scleroderma have a positive antinuclear antibody, and there can be family histories of other connective tissue diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. Some patients have features of scleroderma and other autoimmune conditions. This article will review recent literature to help in the understanding of scleroderma with overlap features. Recent reports of scleroderma overlap with rheumatoid arthritis suggest distinct features of diffuse scleroderma with positive Scl-70, pulmonary fibrosis, and later seropositive erosive rheumatoid arthritis. SLE rarely occurs with scleroderma. Sjögren syndrome symptoms are common in scleroderma. In primary Sjögren syndrome, anticentromere antibody positive patients have more Raynaud phenomenon. Antibodies that occur in scleroderma that are thought to be specific are present in other connective tissue diseases. For instance, Scl-70 antibody is reported in as many as 35% of patients with scleroderma but can be present in 25% of patients with SLE. Myositis or myopathy can be features of scleroderma. Scleroderma overlap with polymyositis is frequently anti-PM Scl antibody positive, whereas anti-Jo-1 does not normally occur in the overlap of scleroderma and polymyositis but is usually exclusively positive in polymyositis with arthritis and alveolitis. A better prognosis is found with PM Scl antibody in myositis. Vasculitis is not a typical feature of scleroderma, but has been reported. Eosinophilic fasciitis is rare, and the onset could be associated with simvastatin.