For patients and relatives

What is myositis?

Myositis is an inflammation of muscular tissue, leading to weakness. Depending on the form of myositis, these diseases are characterized by weakness of the arms and legs.


How do I get myositis?

The definitive cause for myositis is not known. It is an autoimmune condition, meaning that immune cells attack muscles and other tissues of the patients’ own bodies. A first manifestation may be triggered by a stressful event, such as a severe infection, an operation or any other event where the immune system is strongly activated.


How is the diagnosis made?

Usually, an expert physician familiar with these diseases, such as a neurologist or rheumatologist, is required to secure the diagnosis. Besides history taking and a physical examination, laboratory tests (tests for autoantibodies), imaging (sucha s magnetic resonance imaging), and other investigations are usually needed. For a definite diagnosis, a muscle biopsy is frequently performed and send to a pathologist in an attempt to distinguish between the many possible entities.


How can myositis be treated?

Treatment usually consists of a combination of therapies. The most frequently applied treatment consists of glucocorticoids, such as prednisone. Since these have potential side-effects in the long-term, other drugs that suppress the overreactive immune system (immunosuppressives) are required for long-term disease control.