Myositis and Rhabdomyolysis

Myositis is a debilitating muscle disease that causes muscle tissues to degenerate. As the disease progresses, it destroys muscle fiber throughout the body, making even basic physical activities difficult. Although, the effects of myositis are generally confined to the skeletal muscles, the disease can also affect the heart (a large muscle) as well as other tissues such as the lungs and skin.

Symptoms of Myositis

Some possible symptoms of myositis include:

Fatigue
Rashes
Thickening of skin on hands
Swallowing difficulty
Breathing difficulty

Causes of Myositis

Some possible causes of myositis include:

Inflammatory conditions
Infection
medications/ drugs

Rhabdomyolysis

If myositis becomes severe it could develop into rhabdomyolysis, a condition in which muscle fibers released into the circulatory system are toxic to kidney function and can lead to kidney failure. For example, in August 2001, Bayer Pharmaceuticals voluntarily recalled its cholesterol-lowering drug Baycol, after reports of fatal deaths from rhabdomyolysis in patients taking the drug.

Symptoms of Rhabdomyolysis

Common symptoms of rhabdomyolysis include:

Muscle aches
Muscle pain
Stiffness
Dark or red urine color

Causes of Rhabdomyolysis

There are many causes of rhabdomyolysis. Some of these include:

Medications (prescription and over the counter)
Lack of blood perfusion to a limb
Viruses and bacteria
Muscle trauma or injury
Burns
Low thyroid hormone levels (hypothyroidism)