The inflammatory myopathies are a group of muscle diseases that involve inflammation of the muscles or associated tissues, such as the blood vessels that supply the muscles. A myopathy is a muscle disease, and inflammation is a response to cell damage. The inflammatory process leads to the destruction of muscle tissue and is accompanied by weakness and sometimes pain.
Over time, there can be loss of muscle bulk (atrophy). Normally, we think of inflammation, such as that following a sprained ankle or a dental procedure, as a condition that makes a part of the body hot, red and painful to touch. But inflammation can also be internal, causing tissue destruction in various organs.
The common denominator in both types of inflammation is the presence of cells of the immune system in great numbers. Under a microscope, these can be seen “invading” the tissue as an army invades a city. Another word for inflammatory myopathy is myositis. The myo root means muscle, and the itis root means inflammation; so a myositis is an inflammatory muscle disease. Fortunately, for two of the three inflammatory myopathies in MDA’s program — polymyositis (PM) and dermatomyositis (DM) — effective treatments are available.
New research is rapidly leading to increased understanding of these disorders and more successful treatments for them. Although inflammatory myopathies can lead to great discomfort for at least a period of time, for the most part, they aren’t life-threatening. In fact, many people recover partially or completely from PM and DM. The third inflammatory myopathy, inclusion body myositis (IBM), also isn’t life-threatening.
