What is (are) Inflammatory Myopathies ?
The inflammatory myopathies are a group of diseases, with no known cause, that involve chronic muscle inflammation accompanied by muscle weakness. The three main types of chronic, or persistent, inflammatory myopathy are polymyositis, dermatomyositis, and inclusion body myositis (IBM). These rare disorders may affect both adults and children, although dermatomyositis is more common in children. Polymyositis and dermatomyositis are more common in women than in men. General symptoms of chronic inflammatory myopathy include slow but progressive muscle weakness that starts in the proximal musclesthose muscles closest to the trunk of the body. Other symptoms include fatigue after walking or standing, tripping or falling, and difficulty swallowing or breathing. Some patients may have slight muscle pain or muscles that are tender to the touch. Polymyositis affects skeletal muscles (involved with making movement) on both sides of the body. Dermatomyositis is characterized by a skin rash that precedes or accompanies progressive muscle weakness. IBM is characterized by progressive muscle weakness and wasting. Juvenile myositis has some similarities to adult dermatomyositis and polymyositis.