Pyogenic psoas abscess: analysis of 27 cases.

From 1993 to 1998, 29 pyogenic psoas abscesses occurring in 27 patients were seen in Taichung Veterans General Hospital. Their age range was 25 to 85 years. Diabetes mellitus was the leading underlying disease. Fever and pain in the flank area, back and hip were the usual manifestations. The duration of symptoms prior to the diagnosis ranged from 3 days to 6 months. Most abscesses were diagnosed by computed tomography (CT) images and proven by abscess cultures, which were divided into primary and secondary types. Eighteen of 29 abscesses were regarded as primary. Staphylococcus aureus was the most common pathogen in the primary abscesses, followed by Streptococcus agalactiae, Escherichia coli, viridans streptococci, S. epidermidis, and Salmonella spp.. In the secondary abscess category, E. coli was the leading organism in this series, followed by S. aureus, Klebsiella pneumoniae, viridans streptococci and Candida albicans. The associated conditions included epidural abscess, osteomyelitis, septic arthritis, perirenal abscess, pulmonary tuberculosis, empyema, hydronephrosis and trauma history. The initial empiric therapy comprised mostly of cefazolin or oxacillin with or without an aminoglycoside. Thirteen patients underwent percutaneous drainage, while six received surgical debridement, including two with a recurrent abscess. One patient had both drainage and debridement. Others received medical treatment only. Two of the patients with primary abscess died in spite of percutaneous drainage. Therefore, open drainage, besides appropriate antibiotic treatment, is still required to control complex abscesses with sepsis.