Purpose of review: This review discusses the most updated literature of muscle disease in scleroderma in the past year.
Recent findings: In the past year, two studies have highlighted that fibrosis is a prevalent histopathologic feature in muscle biopsies of patients with scleroderma muscle disease. In addition, microangiopathy was a common co-feature on muscle biopsies. A fibrosing myopathy, or fibrosis predominance on muscle histopathology, is associated with a unique clinical phenotype in patients with scleroderma. When compared with those with an inflammatory myopathy, patients with a fibrosing myopathy tend to have diffuse scleroderma, lower muscle enzymes, nonirritable myopathy, and elevated cardiac enzymes. These patients are also reported to have a higher risk of cardiopulmonary complications and cardiac death when compared with those with an inflammatory myopathy.
Summary: Although there are clear cases of overlap myositis, it is clear that muscle disease in scleroderma is being redefined, and it is crucial to start recognizing that the muscle is an organ that can directly be affected by scleroderma. Fibrosis can occur early in scleroderma muscle disease, and a unique histologic subtype of muscle disease, fibrosing myopathy, is associated with a higher risk of mortality.