Tropical pyomyositis of the iliacus muscle in American Samoa

Ten cases of pyomyositis of the iliacus muscle are described in otherwise healthy young Samoans. The correct diagnosis was frequently delayed. Staphylococcus aureus was the most common pathogen isolated from drained abscesses. Preference for hip flexion was seen in six patients, and localized pain or induration at the anterior superior iliac spine were found in seven patients. These clues may help expedite a correct diagnosis.