A Diabetic Man with Abdominal Pain

Diagnosis: emphysematous pyelonephritis. The abdominal radiograph showed small air pockets over the left side of the abdomen, surrounding the shadow of the left kidney (figure 1). Abdominal CT revealed gas accumulation around the left kidney, extending to the retroperitonium and intraperitoneum, suggestive of emphysematous pyelonephritis (figures 2 and 3). Emphysematous pyelonephritis is a rare but potentially lifethreatening disease that is characterized by gas accumulation in renal parenchyma or perirenal space [1, 2]. It occurs mainly in diabetic patients who usually present with fever and flank pain, mimicking uncomplicated urinary tract infection [3, 4]. Peritonitis with diffuse abdominal pain is less common and may be caused by air leakage from the retroperitoneum to the intraperitoneal space through the lesser sac [3, 5]. The most common pathogen involved in emphysematous pyelonephritis is Escherichia coliy followed by Klebsiella pneumoniae [3]. In our patient, blood and urine cultures all grew K. pneumoniae. Diagnosis of emphysematous pyelonephritis is difficult without the aid of imaging studies. Delayed diagnosis may lead to increased morbidity and mortality [6]. CT is considered to be the best imaging modality for diagnosis, because it shows air in the renal parenchyma or perirenal space [7]. In cases in which there is a high clinical suspicion of emphysematous pyelonephritis, an abdominal radiograph may play a role in diagnosis by revealing extraluminal air around the renal shadow [8], as in our patient. The recommended treatment for emphysematous pyelonephritis is a regimen of strong antibiotics with adequate drainage. Selective nephrectomy should be considered in high-risk patients who are experiencing shock, thrombocytopenia, acute