myositis

myositis

Inflammation of muscle tissue, often from bacterial, viral, or parasitic infection but sometimes of unknown origin. Most types destroy muscle and surrounding tissue. Bacteria may directly infect muscle (usually after injury) or produce substances toxic to it. Some chronic diseases (e.g., tuberculosis, third-stage syphilis) can involve the muscles. Parasites (e.g., tapeworms, protozoans) in contaminated food enter the bloodstream from the intestines and lodge in muscle.