Table 1: Classification of inflammatory myositis
(This list is not complete. Its length is to serve as a reminder of the many potential a etiological causes of inflammatory changes in the muscle)

Idiopathic inflammatory myopathies
  Polymyositis
  Dermatomyositis
  Myositis associated with collagen vascular disease
  Myositis associated with malignancy
  Inclusion body myositis
   
Other forms of inflammatory myopathy
  Myositis associated with eosinophilia
  Myositis ossificans
  Focal myositis
  Giant cell myositis
   
Myopathies caused by infection
  Viral, e.g. adenovirus, coxsackievirus, cytomegalovirus, Epstein-Barre virus
  Bacterial, e.g. borrelia burgdorferi, clostridium perfringens, mycobacterium
  Fungal, e.g. cryptococcus
  Parasitic, e.g. microsporidia, schistosoma, toxoplasmosis
  Helminthic, e.g. echinococcus, trichinella
   
Myopathies caused by drugs and toxins
  e.g. Alcohol, amiodarone, chloroquine, colchicine, cyclosporine, gold, penicillamine, vincristine