Psoas abscess caused by actinomycete together with Escherichia coli infection: a case report and literature review.

Psoas abscesses are classified into primary or secondary according to infectious etiology. However, the psoas abscess caused by actinomycete together with Escherichia coli infection is very rare. Here we report a case of psoas abscess caused by actinomycete together with Escherichia coli infection in a young woman. The disease was treated successfully. A literature review of psoas abscess in relation to its etiology, identification, and difficulties in the treatment is also presented.