What is Polymyositis?

Polymyositis is an inflammatory disease which involves the muscles. Patients with this condition experience progressive muscle weakness, usually starting in the trunk of the body. Several treatment approaches can be used to manage this condition, and in some patients it is possible to achieve a complete remission, especially when intervention is provided early, before the muscles have become severely damaged.

Sometimes known as idiopathic inflammatory myopathy, polymyositis usually appears later in life, although it can sometimes emerge in very young children. The earliest symptoms are usually weakness and fatigue. The patient may have difficulty walking or raising the arms above the head, and may have experienced a fall related to muscle weakness. Over time, the muscle weakness can become progressively more debilitating. Polymyositis can also be combined with a skin rash, in which case it is known as dermatomyositis.

This condition occurs when white blood cells invade the muscle tissue, and it is classified as an autoimmune disease. The causes of polymyositis are not fully understood. In some cases, it appears to have a genetic component, and it can also be linked to the presence of some infectious diseases. In other cases, it appears at random and there is no clear explanation or cause for why the condition emerged. A doctor will usually attempt to determine the cause of the condition to ensure that the most appropriate treatment is provided to the patient and so that an underlying medical problem will not go untreated.

A doctor can diagnose polymyositis with the assistance of a patient interview, a physical assessment, bloodwork, and a muscle biopsy which will allow a pathologist to examine the patient's muscle tissue for signs of polymyositis. Treatment can include corticosteroids to reduce the inflammation and make the patient more comfortable, and immune suppressants may be used to reduce the activity of the patient's immune system to prevent additional damage. Physical therapy may also be used to help patients build up muscle strength and relearn muscle movements.

This condition is more common in women than men, and it can be associated with complications such as respiratory failure. If polymyositis is diagnosed and treated early, a patient may experience no long-term effects, and can enjoy a full and healthy life with a normal activity level. Other patients may need to adjust their activity levels and lifestyles to cope with the disease, and patients with severe forms are at risk of more serious complications.