ABSTRACT
Psoas abscess is rarely encountered with various etiologies and nonspecific clinical presentation, frequently resulting in delayed diagnosis, with increased morbidity and mortality. Two types of psoas abscess are recognized. The primary psoas abscess is generally following hematogenous dissemination of an infectious agent and the source is usually occult. The most frequently isolated pathogen is Staphylococcuss aureus. On the other hand, the secondary abscess is the result of local extension of an infectious process near the psoas muscle, especially in diabetes, malnutrition, alcoholism, and steroid abuse. A 83-year-old woman presented with high fever and progressive back pain. Abdominal CT scan showed bilateral psoas abscesses combined with lobulated kidney. Both cultures of blood and urine showed Klebsiella pneumoniae. By prolonged antibiotic treatment and abscess drainage, she showed clinical, and radiological improvement. Here, we report an unusual case of bilateral pyogenic psoas abscess complicated by acute pyelonephritis due to Klebsiella pneumonia.