Unusual X-Ray Finding in Pseudomembranous Enterocolitis

Four days after having been given cefuroxime for sinusitis, a 49-year-old woman experienced abdominal cramping, diarrhea, fever (temperature of 39.4°C [103°F]), and nausea. These problems persisted for 1 week, at which time the patient arrived at the emergency department. She had no recent history of travel, ingestion of undercooked food, or exposure to anyone with similar digestive problems.

Because a stool sample was positive for Clostridium difficile, the cefuroxime was discontinued. An abdominal x-ray film showed multiple thumbprinting (arrows) along the ascending and descending colon. Therapy with oral metronidazole was begun, and the patient made a full recovery. A follow-up abdominal film showed that the thumbprinting sign had disappeared.

This patient had pseudomembranous enterocolitis, an inflammatory bowel disorder marked by membranous, yellowish plaques of exudate that overlie and replace necrotic intestinal mucosa. Of the three types of pseudomembranous enterocolitis-neonatal, postoperative, and drug-induced-the last is by far the most common. The use of almost any antibiotic, including metronidazole, can lead to this condition by inducing overgrowth of normal intestinal flora-particularly C difficile. Inflammation results in microthrombosis, which generates ischemia in the affected colon.

The disease typically begins 7 to 10 days after initiation of antibiotic therapy; its manifestations range from frequent mucoid, watery stools to a toxic condition that includes profuse diarrhea, crampy abdominal pain, fever, leukocytosis, dehydration, and hypovolemia. The history of antibiotic use and endoscopic evidence provide the diagnosis.

The thumbprinting sign represents thick, edematous mucosal folds induced by inflammation. Although it is a typical manifestation of mesenteric ischemia or infarction on a barium study, it is an extremely rare finding on a plain abdominal film, writes Dr Ibrahim Seki of Allentown, Pa.