Pyomyositis is a bacterial infection of the skeletal muscles which results in an abscess.

Primary pyomyositis is a skeletal muscle infection arising from hematogenous infection, whereas secondary pyomyositis arises from localized penetrating trauma or contiguous spread to the muscle.

[6][7] Infection often follows minor trauma and is more common in the tropics, where it accounts for 4% of all hospital admissions.

In temperate countries such as the US, pyomyositis was a rare condition (accounting for 1 in 3000 pediatric admissions), but has become more common since the appearance of the USA300 strain of MRSA.

[2][4][5] Gonococcal pyomyositis is a rare infection caused by Neisseria gonorrhoeae.