Epidemiology of myositis.

Purpose of review: This review aims to synthesize recent developments in the epidemiology of idiopathic inflammatory myopathies (IIMs), focusing on incidence, prevalence, disease classification, and clinical outcomes.

Recent findings: IIM is a rare group of autoimmune diseases characterized by muscle weakness and systemic involvement, with incidence rates ranging from 0.2 to 2 cases per 100 000 person-years. The role of myositis-specific autoantibodies (MSAs) in stratifying disease risk and prognosis is increasingly recognized, such as in anti-MDA5 positive DM, which is associated with a high risk of rapidly progressive interstitial lung disease. Furthermore, patients with IIM exhibit elevated risks of comorbidities, including cardiovascular disease and malignancy.

Summary: IIM diseases are complex disorders with significant health impacts, necessitating enhanced awareness and research. Improved classification and understanding of MSAs are crucial for earlier diagnosis and tailored therapeutic strategies. Continued epidemiological research is essential to elucidate underlying mechanisms and inform future interventions, ultimately aiming to enhance the quality of life and clinical outcomes for affected patients.