Natural History of Inflammatory Muscle Diseases

This is a natural history study — meaning it follows people over time without giving any experimental treatment — focused on inflammatory muscle diseases, collectively called inflammatory myopathies. These are rare autoimmune conditions where the immune system mistakenly attacks muscle tissue, causing weakness, fatigue, and sometimes damage to other organs like the lungs and skin. Conditions included are polymyositis, dermatomyositis, and related disorders. By collecting clinical data, biosamples, and assessments over time, researchers aim to better understand how these diseases progress and what factors predict outcomes. Adults and young people aged 12 and older with possible or confirmed inflammatory myopathy are eligible, as are healthy adult volunteers (18 and older) for comparison. The only exclusion criterion is unwillingness to participate or provide research samples — making this a broadly accessible study. Participants attend periodic study visits where clinical assessments, blood draws, and other measurements are collected. No experimental treatments are administered. This research is vital because inflammatory myopathies are poorly understood, often misdiagnosed, and can be difficult to treat. Long-term, detailed natural history data is essential for developing better diagnostic tests, identifying new treatment targets, and designing future clinical trials.