Myopathy in certain specified infectious or parasitic disease

**Definition:** Myopathy in certain specified infectious or parasitic disease is an uncommon group of muscle diseases caused by a broad range of bacterial, fungal, parasitic, and viral agents. Bacterial organisms cause pyomyositis, psoas abscess, Staphylococcus aureus myositis, group A streptococcal necrotizing myositis, group B streptococcal myositis, clostridial gas gangrene, and nonclostridial myositis. Fungal myositis is rare and usually occurs among immunocompromised hosts. Parasitic myositis is most commonly a result of trichinosis or cystericercosis, but other protozoa or helminths may be involved. Viruses may cause benign acute myositis, pleurodynia, acute rhabdomyolysis, or an immune-mediated polymyositis.

**Exclusions:** - Myasthenia gravis or certain specified neuromuscular junction disorders - Primary disorders of muscles