Psoas abscess: changing patterns of diagnosis and etiology.

From 1976 to 1984, 43 patients with psoas abscess were seen at the Mayo Clinic. Intestinal disease, including Crohn's disease, diverticulitis, and carcinoma, was the most frequent cause (14 patients). Eleven patients had osteomyelitis, five had postoperative complications, four had a foreign-body reaction, and three had a primary staphylococcal abscess. Two patients each had extension of a primary pancreatic and perinephric abscess. One patient had tuberculosis of the spine, and in the remaining patient, an exact cause was not determined. Definitive treatment of psoas abscess includes adequate debridement, drainage of the abscess cavity, and resection of involved bowel.