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OVERVIEW
This page is dedicated to organizing various examples of standardized exam questions whose answer is Crohn disease. While this may seem a odd practice, it is useful to see multiple examples of how Crohn disease will be characterized on standardized exams (namely the boards and the shelf exams). This page is not meant to be used as a traditional question bank (as all of the answers will be the same), however seeing the classic “test” characterization for a disease is quite valuable.
KEY CHARACTERISTICS OF THIS CONDITION (ON EXAMS)
When it comes to standardized exams, each condition has its own “code” marked by key buzzwords, lab findings, clues, etc. If you are well versed in this code you will be able to more quickly identify the condition that is being discussed, and get the right answer on the exam you are taking. Below is the “code” for Crohn disease.
Chief Complaints:
- Abdominal pain often that is vague/difficult to characterize. Can be crampy in nature.
- Diarrhea can often be accompanied by weight loss
- Extraintestinal manifestations: arthritis (joints), uveitis (eyes), pyoderma gangrenousum/erythema nodosum (skin), primary sclerosing cholangitis
- Blood in stool may or may not be present. Typically occult blood is positive (but not GROSSLY positive like in ulcerative colitis)
Clinical Workup:
- Fistula formation: may be seen on the physical exam (bowel contents draining through skin), or on imaging etc. Fistula formation is very specific to this condition!
- Lead pipe colon can be seen on a barium enema (gross inflammation of colon walls gives “smooth” appearance of the colon)
- Full thickness inflammation with granuloma and typhoid aggregate formation seen on histology . Non-caseating granuloma is characteristic for this condition.
QUESTION EXAMPLES
Question # 1
A 30 year old male complains of low grade fever, diarrhea, and a vague abdominal pain which is difficult to characterize. He is sent how without any treatment. A few weeks after this, he develops a skin lesion over his lower abdomen. Currently his temperature is 99.9°F, blood pressure is 125/75 mm Hg, and his pulse is 85 bpm. A physical exam reveals an abdomen that is mildly distended, with slight diffuse tenderness to palpation. Bowel contents can be seen draining through the surface of his skin at the site of his abdominal lesion. What is the likely diagnosis in this patient?
Explanation # 1
Diarrhea + abdominal pain + enterocutaneous fistula = Crohn disease
Question # 2
A 35 year old male presents with abdominal pain and also complains of intermitted diarrhea. He is found to have occult blood in his stools. Stool cultures are sent but do not grow out any organisms. A colonoscopy is performed and his colonic mucousa is biopsied. An image of biopsied tissue is shown below:
What is the likely diagnosis in this patient?
Explanation # 2
Diarrhea + abdominal pain + non-caeseating granuloma in bowel (seen histologically) = Crohn disease
Question # 3
A 3o year old female has right lower quadrant pain and eventually undergoes laparotomy for further investigation. She is found to have a swollen and inflamed terminal ileum. This segment of bowel is removed and observed histologically. A representative slide is shown below.
What is the likely diagnosis in this patient?
Explanation # 3
Abdominal pain + non-caeseating granuloma in bowel (seen histologically) = Crohn disease
Question # 4
A 24 year old woman is seen in the clinic for abdominal pain that is periodic in nature, and has been present for the past few years. She explains that the pain is crampy in nature, and is associated with fluctuating diarrhea. She denies seeing any blood in her stool, nausea, vomiting, or constipation. The patient’s last period was 1 week ago. Her past medical history is non-contributory, and she denies using any tobacco products or drinking alcohol. Her vitals are currently within normal limits. Her physical exam reveals a tender abdomen without any rebound tenderness or guarding. A draining fistula is seen near the patient’s coccyx. What is the likely diagnosis in this patient?
Explanation # 4
Diarrhea + abdominal pain + enterocutaneous fistula = Crohn disease
Question # 5
A 25 year old male is seen int he clinic because he has been complaining of intermittent abdominal pain and fluctuating diarrhea for the past 6 months. He explains that he has lost about 12 lbs in this period of time. Currently his vital signs are all within normal limits. Lab values reveal a white count of 13,000/mm³ and a hemoglobin of 13.1 g/dL. A barium enema is shown below.
What is the likely diagnosis in this patient?
Explanation # 5
Diarrhea + abdominal pain + lead pipe colon (barium enema) = Crohn disease
Question # 6
A 30 year old female complains of intermittent abdominal cramps that seem to be progressively worsening. She also has a history of intermittent diarrhea that seems to be associated with a 14 lb weight loss over the past year. A physical exam shows generalized abodminla tenderness, but there is no rebound tenderness or guarding. There is pronounced tenderness in the right lower quadrant. A barium enema is conducted and shown below.
What is the likely diagnosis in this patient?
Explanation # 6
Diarrhea + abdominal pain + lead pipe colon (barium enema) = Crohn disease
TESTABLE FACTS ABOUT THIS CONDITION (BEYOND ITS IDENTIFICATION)
Many questions on standardized exams go beyond simply recognizing the underlying condition. Often there are specific testable facts regarding some aspect of the disease’s pathophysiology/management/clincial implications that are commonly asked. Some of these are listed below:
Classic Gross/Histological Appearance:
- Skip lesions: not continuous involvement. Clear areas of demarcation between normal and affected boweol.
- Cobblestone appearance of mucousa: appreciated grossly. Long serpiginous or liberal ulcerations spare intervening mucousa and lead to areas of nodular thickening.
- Transmural inflammation: full thickness of the intesntial wall
- Non-caseating granulomas: are very characteristic
Other
- Common vitamin deficiencies: vitamin A (fat malabsorption), vitamin B12
- Common complications: perianal fistulas
Page Updated: 04.02.2017