Eosinophilic Fasciitis: New Developments and Future Directions

Eosinophilic fasciitis (EF), also known as Shulman's disease, is a rare, autoimmune sclerosing connective tissue disorder. The purpose of this review is to provide clinicians with a comprehensive summary of the latest information on the diagnosis and management of EF. The pathogenesis of EF is unclear; however, it is believed to involve increased fibroblast activity and interleukins linked to eosinophilia, such as interleukin (IL)-5. While mostly idiopathic, triggers include exercise, trauma, infection, and specific medications. The disease is typically characterized by erythema, edema, and induration of extremities, with laboratory findings including peripheral eosinophilia and hypergammaglobulinemia. EF is typically mistaken for other sclerosing diseases, such as systemic sclerosis and morphea. Diagnostic workup for EF may include an initial complete blood count (CBC) with differential, followed by erythrocyte sedimentation rate and aldolase to classify severity, and a systemic hematologic workup if indicated. A full-thickness skin-to-muscle (including fascia) incisional biopsy is the diagnostic gold standard though magnetic resonance imaging (MRI) may be highly sufficient. Ultrasound presents as an accessible tool for determining the biopsy site and supporting a diagnosis of EF. While commonly treated with corticosteroids and methotrexate, studies have revealed that many patients are refractory to these traditional therapies. Biologic therapies have shown utility in treatment-resistant EF, often resulting in at least partial resolution of their disease. The long-term prognosis for EF is reliant on treatment and its timelines. Complications, such as decreased range of motion, can significantly impact patients' quality of life. Further research should focus on understanding EF pathogenesis, diagnostic strategies for early detection, and assessing newer therapies in prospective clinical trials.