Childhood polymyositis: a case-control study.

A case-control epidemiologic study of childhood polymyositis is presented. Parents of 42 cases of childhood polymyositis were interviewed along with parents of controls matched for sex and age. Extensive review of past medical history, animal exposure history, residential and family history, and immunization history failed to reveal any significant differences between the two groups. The only suggestive difference was exposure to bacteriologically confirmed streptococcal diseases in 20 cases as compared to 13 controls.