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Cause of Polymyositis

Polymyositis is an autoimmune disorder, meaning that a person's white blood cells which are supposed to fight off bacteria and viruses begin attacking their own muscles. While we do not know what triggers a person’s immune system to behave in this way there are many theories that suggest the cause of Polymyositis is a combination of one’s genetic predisposition and environmental exposures. People of either sex or any age can get polymyositis, but it is slightly more common in females, and people in middle childhood and their 20s. It is sometimes associated with other autoimmune diseases such as sometimes connected with lupus, scleroderma, and rheumatoid arthritis. In rare cases it can be associated with certain types of cancers.

Syndrome	Distinctive features
Idiopathic	Proximal weakness; High CK; Inflammatory myopathy
Collagen vascular disease	Myalgias; Younger onset Scleroderma & Mixed connective tissue disease
Anti-t-rna synthetase antibodies Jo-1 antibodies	Interstitial pneumonitis; Raynauds; Arthritis Perimysial pathology
Signal recognition particle antibody	Acute onset; Severe weakness Capillary pathology; Fibrosis
MAS antibody	Acute onset; Rhabdomyolysis
Drug-induced	D-penicillamine
Familial	Homozygosity at HLA-DQA1 locus
Graft-vs-host disease	7 to 24 months post BMT
Granulomatous	Sarcoid; Immune; Infections
Sarcoidosis	Myopathy; Neuropathy; Lung disease
Malignancy (Necrotic)	Rapid onset; Older patients; Necrotic myopathy
Mitochondrial (P-COX)	Quadriceps weakness; Older onset age; Steroid resistant
Other systemic disorders	HIV; Fasciitis

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Cures for Polymyositis
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