What are the causes and symptoms of myositis?
Myositis is thought to be an autoimmune disease. The body normally fights infections and disease by producing antibodies and white blood cells called lymphocytes in a process called the immune response. In an autoimmune disease, the immune response is overactive, and the immune system attacks and destroys the body’s own normal healthy tissues. There is no known cause to the autoimmune response that results in myositis. However, investigators are studying whether the disease is triggered by such environmental agents as the organism that causes toxoplasmosis, Toxoplasma gondii, the Lyme disease organism, Borrelia burgdorferi, the coxsackievirus, or by food allergies. Some cases of IBM are thought to be inherited. The first symptoms of most types of myositis are weakness and pain in the muscles of the hips and shoulders. The affected person may have trouble getting up from a chair, lifting the arms above the head, or climbing stairs, and may be too tired to walk or stand. DM and PM mostly
