Review Question - QID 101084

The clinical scenario and radiograph findings are consistent with Crohn's disease.

Crohn's disease is a subtype of inflammatory bowel disease due to an inappropriate immune response against intestinal bacteria. In contrast to ulcerative colitis, Crohn's affects the entire length of the GI tract and the GI wall in its entirety. Fistula and stricture formation lead to the obstructive symptoms of colicky pain and the characteristic "string" sign on barium swallow.

Wilkins et al. report that the extraintestinal manifestations of Crohn's disease include osteoporosis, inflammatory arthropathies, scleritis, nephrolithiasis, cholelithiasis, and erythema nodosum. Erythema nodosum, as described in this patient, is an inflammation of the fat cells under the skin, resulting in characteristic tender, red nodules usually seen on both shins.

Lichtenstein et al. review the diagnosis of Crohn's disease. They report that the diagnosis is based on the combined findings of focal, asymmetric, transmural, or granulomatous features on endoscopy, radiography, and pathology. Forms of intestinal infections and other types of colitis must be ruled out.

Figure A is a radiograph after barium study illustrating Crohn's disease of the colon and ileum. The typical 'string sign' of distal ileal narrowing is present. Illustration A shows erythema nodosum on a woman's shins.

Incorrect Answers:
Answer 1: Ulcerative colitis involves only the colon and has a characteristic "lead pipe" appearance on radiography.
Answer 2: Irritable bowl syndrome is defined by chronic cycling abdominal pain without any structural abnormalities.
Answer 3: Celiac disease is an autoimmune reaction against gliadin in wheat that causes malabsorption. Celiac disease is associated with dermatitis herpetiformans, not erythema nodosum and is not associated with stricture or fistula formation.
Answer 4: In Hirshprung disease, failed neural crest cell migration results in an aganglionic distal colon that cannot relax. Congenital megacolon results proximally and presents early in life.