Thursday, December 23, 2010

Clinical case: A young woman with recurrent episodes of diarrhea, crampy abdominal pain, and slight fever over the last 2 years....

Clinical Vignette: A 22-year-old woman has had recurrent episodes of diarrhea, crampy abdominal pain, and slight fever over the last 2 years. At first the episodes, which usually last 1 or 2 weeks, were several months apart, but recently they have occurred more frequently. Other symptoms have included mild joint pain and sometimes red skin lesions. On at least one occasion, her stool has been guaiac-positive, indicating the presence of occult blood. Colonoscopy reveals several sharply delineated areas with thickening of the bowel wall and mucosal ulceration. Areas adjacent to these lesions appear normal. Biopsies of the affected areas show full-thickness inflammation of the bowel wall and several noncaseating granulomas.

◆ What is the most likely diagnosis?
◆ What are the common complications of this disease?

Summary: A 22-year-old woman has a 2-year history of recurrent diarrhea, abdominal pain, slight fever, joint pain, and red skin lesions. Colonoscopy reveals several sharply delineated areas with thickening of the bowel wall and mucosal ulceration, which on biopsy show full-thickness inflammation of the bowel wall and several noncaseating granulomas.

Most likely diagnosis: Crohn disease
Common complications of this disease: Malabsorption and 
malnutrition, fibrous strictures of the intestine, and fistulae to other organs, such as from bowel to skin or bowel to bladder
This clinical vignette test a very common question asked on the USMLE step 1.

The patient’s presentation is very characteristic for inflammatory bowel disease, that is, a several-year history of diarrhea and abdominal pain.
Additionally, the colonoscopy revealing full-thickness inflammation with non-caseating granulomas is consistent with Crohn disease. Crohn disease is a chronic inflammatory condition that is ubiquitous in its distribution in the gastrointestinal tract. It most commonly manifests in the small intestine, in particular the terminal ileum. The disease exhibits aggressive activity of the gastrointestinal immune system, but the exact cause is unknown. Published studies in the United States report incidence rates that vary between 1.2 and 8.8 per 100,000 population; the prevalence is 44 to 106 per 100,000. The condition is more common in the cold climates of the northeastern United States than in the south. Those of Jewish ethnicity have a high incidence. The disorder, which is slightly more common in females, has a bimodal age distribution, peaking in the early twenties and again emerging in the mid-sixties. Theories 
regarding pathogenesis have referred to genetics, infection, autoimmune or allergic processes, thromboembolic disorders, and dietary disorders.