Psoas abscess: a 10 year review.

Psoas muscle abscesses are rarely encountered yet, and pose diagnostic and therapeutic challenges because of nonspecific clinical presentations. We retrospectively reviewed the medical records of adults with a psoas muscle abscess who were admitted to our hospital from January, 1988 to May, 1998. Over this ten year period, psoas abscesses were found in 11 cases. Six cases were primary and Staphylococcus spp. was the most commonly isolated. Five cases were a secondary psoas abscess while urological problems were the most common underlying condition. Fever, chills, lower back or flank pain and a palpable mass were the most common manifestations. Only one patient presented the classic triad of fever, flank pain, and limitation of hip movement (a typical psoas sign). Leukocytosis was the most common laboratory finding. Two of 11 cases presented septic shock. Two patients were admitted to the hospital with the initial diagnosis of psoas abscesses. Computerized tomographic (CT) scans accurately confirmed the clinical diagnosis in 9 of 11 patients. Diagnosis was then established one each by ultrasound (US) and magnetic resonance imaging (MRI), respectively. Four of 11 patients had negative findings initially by US. All patients were managed with drainage and antibiotics, nine were drained surgically, and two were managed with percutaneous drainage under CT guidance. Two patients died. Because of the lack of the classic symptoms and signs in most cases, a high degree of suspicion is important for early diagnosis of psoas abscess. CT scan is the standard technique of diagnosis. The prognosis is generally good with appropriate antibiotic treatment and complete drainage.