MKSAP Quiz: Worsening abdominal pain

A 26-year-old woman with Crohn disease is evaluated for a 2-week history of worsening abdominal pain. The patient has required three courses of prednisone for disease flares over the past year. Her only medication is azathioprine. What is the most appropriate treatment?


A 26-year-old woman with Crohn disease is evaluated for a 2-week history of worsening abdominal pain in the right lower quadrant. She reports passage of one to two formed and nonbloody stools per day with no changes in bowel habits. The patient has required three courses of prednisone for disease flares over the past year. Her only medication is azathioprine.

On physical examination, temperature is 37.7 °C (99.9 °F) and pulse rate is 115/min; other vital signs are normal. Abdominal examination shows fullness and tenderness in the right lower quadrant with no distinct mass. The remainder of the examination is unremarkable.

Laboratory studies show a hemoglobin level of 10.5 g/dL (105 g/L) and a C-reactive protein level of 32 mg/dL (320 mg/L). Leukocyte count and liver chemistry tests are normal.

CT enterography shows asymmetric mural thickening and mucosal inflammation of a long segment of distal ileum without luminal narrowing.

Which of the following is the most appropriate treatment?

A. Budesonide
B. Infliximab
C. Mesalamine
D. Prednisone


MKSAP Answer and Critique

The correct answer is B. Infliximab. This content is available to MKSAP 18 subscribers as Question 78 in the Gastroenterology and Hepatology section. More information about MKSAP is available online.

Infliximab is the most appropriate treatment for this patient. This patient has moderate to severe ileal Crohn disease that has required multiple courses of tapering prednisone for flares of disease over the last year, despite treatment with the immunomodulator azathioprine. Infliximab is an anti–tumor necrosis factor (TNF)-α antagonist effective in inducing and maintaining remission in moderate to severe Crohn disease. Other FDA-approved anti-TNF agents include adalimumab and certolizumab pegol. Evidence indicates that efficacy is better when an anti-TNF agent is used together with an immunomodulator. In addition, the risk for developing antibodies against the anti-TNF agent is lower with combination therapy. Patients whose disease does not respond to one anti-TNF agent are often switched to a second or third anti-TNF agent. Fibrostenosing Crohn disease in the absence of ongoing mucosal inflammation is unlikely to respond to any anti-TNF agent. Patients with no response to or intolerance of anti-TNF agents should be treated with either surgery or a leukocyte trafficking blocker (natalizumab or vedolizumab).

Budesonide is a potent glucocorticoid with high first-pass metabolism in the liver, which limits systemic side effects related to conventional glucocorticoids. Budesonide can be an effective therapy for treating mild flares of ileal Crohn disease, but it is unlikely to induce remission in more severe Crohn disease and cannot be used to maintain remission.

Mesalamine agents are mainly used to treat ulcerative colitis of mild to moderate severity. Mesalamine may have efficacy in treating mild to moderate Crohn colitis, but it is not efficacious in treating small-bowel Crohn disease.

Reinitiating prednisone may induce remission of the patient's current disease flare, but it would not be helpful for maintenance of remission. Because this patient has required three separate tapering doses of glucocorticoids over the last year, she requires a medication such as infliximab that can both induce remission and maintain Crohn disease in remission.

Key Point

  • Anti–tumor necrosis factor agents such as infliximab are effective in inducing and maintaining remission in moderate to severe Crohn disease.