Septicemia of unknown origin causing by Streptococcus agalactiae primary psoas abscess: a case report.

Staphylococcus aureus is the commonest organism resulting in primary psoas abscesses. However non-staphylococcal primary psoas abscesses have increasingly been published in the literature. Here, the author reports a case of primary psoas abscess in a type II diabetic woman previously diagnosed Streptococcus agalactiae septicemia of unknown origin, which rapidly responded to penicillin plus clindamycin and prompt surgical drainage. Diabetic patients are not only susceptible to soft tissue infection but also primary psoas abscess caused by Streptococcus agalactiae.