The cases of eighteen patients who were treated for pyomyositis between
1970 and 1988 were evaluated. The diagnosis was often delayed because other
primary diagnoses were considered, including muscle strain, synovitis,
thrombophlebitis, and neoplasm, and because the symptoms were vague and
prolonged (maximum duration, one year). The muscles around the hip and
thigh were most commonly involved (twelve patients), and Staphylococcus
aureus most commonly grew on culture (twelve patients). Computed tomography
aided in the accurate diagnosis of the infection and of the extent of
involvement. Incision, drainage, and antibiotic therapy eradicated the
infection in all patients, and they had no residual functional limitations
and minimum residual symptoms.