A 17-year-old girl is brought to the physician by her parents for the evaluation of belly pain and a pruritic skin rash on her shoulders for the last 6 months. She describes feeling bloated after meals. Over the past 3 months, she has had multiple loose bowel movements per day. She appears thin. She is at the 20th percentile for height and 8th percentile for weight. Her temperature is 37°C (98.6°F), pulse is 90/min, respirations are 16/min, and blood pressure is 120/78 mm Hg. Examination shows conjunctival pallor and inflammation of the corners of the mouth. There are several tense, grouped subepidermal blisters on the shoulders bilaterally. The abdomen is soft, and there is diffuse tenderness to palpation with no guarding or rebound. Further evaluation of this patient is most likely to show which of the following findings?
Q2
A 32-year-old man with Crohn disease is brought to the emergency department after he fainted at work. He says that he has been feeling increasingly fatigued and weak over the last several weeks though he has not previously had any episodes of syncope. On presentation he is found to be pale and agitated. A panel of lab tests is performed showing the following:
Hemoglobin: 10.2 g/dL
Hematocrit: 30.1%
Leukocyte count: 9,900 cells/mm^3 with normal differential
Platelet count: 290,000/mm^3
Mean corpuscular volume: 118 µm^3
Elevated homocysteine level
Normal methylmalonic acid level
Which of the following mechanisms explains how Crohn disease may have contributed to this patient's symptoms?
Q3
A 63-year-old man comes to the physician with a 4-week history of fatigue, crampy abdominal pain, watery diarrhea, and pain in his mouth and gums. He returned from a 2-week trip to the Dominican Republic 2 months ago. He has smoked one pack of cigarettes daily for 45 years. Examination shows three 1.5-cm, painful ulcers in the mouth. Abdominal examination shows mild tenderness to palpation in the right lower quadrant without guarding or rebound. His hemoglobin concentration is 11.2 g/dL, mean corpuscular volume is 75 fL, and leukocyte count is 11,900/mm³. Colonoscopy shows a cobblestone mucosa. A photomicrograph of a biopsy specimen is shown. Which of the following is the most likely diagnosis?
Q4
A 33-year-old man has a history of intermittent bloody diarrhea, tenesmus, fever, fatigue, and lower abdominal cramps for the past 2 weeks. On physical examination, he is lethargic and appears lean and pale. He has aphthous stomatitis, red congested conjunctiva, and tender swollen joints. At the doctor’s office, his pulse is 114/min, blood pressure is 102/76 mm Hg, respirations are 20/min, and his temperature is 39.4°C (102.9°F). There is vague lower abdominal tenderness and frank blood on rectal examination. Laboratory studies show:
Hemoglobin 7.6 g/dL
Hematocrit 33%
Total leucocyte count 22,000/mm3
Stool assay for C.difficile is negative
Abdominal X-ray shows no significant abnormality
He is symptomatically managed and referred to a gastroenterologist, who suggests a colonoscopy and contrast (barium) study for the diagnosis. Which of the following is the most likely combination of findings in his colonoscopy and barium study?
Q5
A 31-year-old woman comes to the emergency department because of a 4-day history of fever and diarrhea. She has abdominal cramps and frequent bowel movements of small quantities of stool with blood and mucus. She has had multiple similar episodes over the past 8 months. Her temperature is 38.1°C (100.6°F), pulse is 75/min, and blood pressure is 130/80 mm Hg. Bowel sounds are normal. The abdomen is soft. There is tenderness to palpation in the left lower quadrant with guarding and no rebound. She receives appropriate treatment and recovers. Two weeks later, colonoscopy shows polypoid growths flanked by linear ulcers. A colonic biopsy specimen shows mucosal edema with distorted crypts and inflammatory cells in the lamina propria. Which of the following is the most appropriate recommendation for this patient?
Q6
A 25-year-old woman presents to the emergency department with fatigue and weakness. She states over the past 24 hours she has not felt like herself and has felt like she has no strength. The patient has no significant past medical history other than a single episode of blood-tinged diarrhea 1 week ago which resolved on its own. Her temperature is 99.4°F (37.4°C), blood pressure is 124/62 mmHg, pulse is 95/min, respirations are 29/min, and oxygen saturation is 95% on room air. Physical exam is notable for 2/5 strength of the lower extremities and decreased sensation in the lower extremities and finger tips. Which of the following is the best initial step in management?
Q7
A 19-year-old woman comes to the physician because of a 1-year history of severe abdominal pain, bloating, and episodic diarrhea. She also has a 10-kg (22-lb) weight loss over the past 10 months. Physical examination shows a mildly distended abdomen, diffuse abdominal tenderness, and multiple erythematous, tender nodules on the anterior aspect of both legs. There is a small draining lesion in the perianal region. Further evaluation of this patient's gastrointestinal tract is most likely to show which of the following findings?
Q8
A 37-year-old man with Crohn disease is admitted to the hospital because of acute small bowel obstruction. Endoscopy shows a stricture in the terminal ileum. The ileum is surgically resected after endoscopic balloon dilatation fails to relieve the obstruction. Three years later, he returns for a follow-up examination. He takes no medications. This patient is most likely to have which of the following physical exam findings?
Q9
A 47-year-old man presents to his primary care physician complaining of pain and stiffness in his right index finger and left knee. The past medical history is remarkable for severe dandruff and an episode of apparent gout in the left 1st toe 6 months ago, which never resolved. The physical examination confirms dactylitis of the right index finger and several toes, as well as synovitis of the left knee. He is also noted to have pitting of his fingernails. Plain X-rays of his hand reveal erosions in the distal interphalangeal (DIP) joint and periarticular new bone formation. Which of the following is most consistent with these findings?
Q10
An otherwise healthy 27-year-old man presents to his dermatologist because of a rash over his knees. The rash has been present for 5 weeks and is moderately itchy. Physical examination reveals erythematous plaques covered with silvery scales over the extensor surface of the knees as shown in the image. Which of the following is the best initial step in the management of this patient’s condition?
IBD US Medical PG Practice Questions and MCQs
Question 1: A 17-year-old girl is brought to the physician by her parents for the evaluation of belly pain and a pruritic skin rash on her shoulders for the last 6 months. She describes feeling bloated after meals. Over the past 3 months, she has had multiple loose bowel movements per day. She appears thin. She is at the 20th percentile for height and 8th percentile for weight. Her temperature is 37°C (98.6°F), pulse is 90/min, respirations are 16/min, and blood pressure is 120/78 mm Hg. Examination shows conjunctival pallor and inflammation of the corners of the mouth. There are several tense, grouped subepidermal blisters on the shoulders bilaterally. The abdomen is soft, and there is diffuse tenderness to palpation with no guarding or rebound. Further evaluation of this patient is most likely to show which of the following findings?
A. Increased serum lipase
B. IgA tissue transglutaminase antibodies (Correct Answer)
C. Oocysts on acid-fast stain
D. Inflammation of the terminal ileum
E. Esophageal webs
Explanation: ***IgA tissue transglutaminase antibodies***
- The patient's symptoms of **belly pain**, **bloating**, **loose bowel movements**, **weight loss**, **growth failure** (low height and weight percentiles), and **pruritic skin rash** (dermatitis herpetiformis) are highly suggestive of **celiac disease**.
- **IgA tissue transglutaminase (tTG) antibodies** are the most sensitive and specific serological test for celiac disease.
*Increased serum lipase*
- **Increased serum lipase** is indicative of **pancreatitis**, which is not supported by the patient's symptoms or physical findings.
- While chronic pancreatitis can cause malabsorption, the characteristic skin rash and other gastrointestinal symptoms do not point to this diagnosis.
*Oocysts on acid-fast stain*
- **Oocysts on acid-fast stain** are used to diagnose **cryptosporidiosis** or other parasitic infections, which can cause chronic diarrhea but typically do not present with a characteristic skin rash like dermatitis herpetiformis.
- The presentation is more consistent with an autoimmune enteropathy rather than an infectious cause.
*Inflammation of the terminal ileum*
- **Inflammation of the terminal ileum** is characteristic of **Crohn's disease**, which can cause abdominal pain, diarrhea, and weight loss.
- However, the pruritic, blistering rash on the shoulders (dermatitis herpetiformis) is a hallmark of **celiac disease** and not typical for Crohn's disease.
*Esophageal webs*
- **Esophageal webs** are associated with **Plummer-Vinson syndrome**, which causes dysphagia and iron deficiency anemia.
- While this patient shows signs of anemia (conjunctival pallor), esophageal webs do not explain the chronic diarrhea, bloating, or the characteristic skin rash.
Question 2: A 32-year-old man with Crohn disease is brought to the emergency department after he fainted at work. He says that he has been feeling increasingly fatigued and weak over the last several weeks though he has not previously had any episodes of syncope. On presentation he is found to be pale and agitated. A panel of lab tests is performed showing the following:
Hemoglobin: 10.2 g/dL
Hematocrit: 30.1%
Leukocyte count: 9,900 cells/mm^3 with normal differential
Platelet count: 290,000/mm^3
Mean corpuscular volume: 118 µm^3
Elevated homocysteine level
Normal methylmalonic acid level
Which of the following mechanisms explains how Crohn disease may have contributed to this patient's symptoms?
A. Gastrointestinal blood loss
B. Inflammation of the ileum
C. Inflammation of the jejunum (Correct Answer)
D. Release of acute phase proteins
E. Inflammation of the duodenum
Explanation: ***Inflammation of the jejunum***
- The patient's **macrocytic anemia** (MCV 118 fL) with **elevated homocysteine** and **normal methylmalonic acid** points to a **folate deficiency**.
- **Folate** is primarily absorbed in the **proximal small intestine**, particularly the **jejunum**; inflammation in this segment due to Crohn's disease would impair its absorption, leading to deficiency.
- While Crohn's disease classically affects the **terminal ileum**, it can involve any part of the GI tract, and **jejunal involvement** would specifically impair folate absorption.
*Gastrointestinal blood loss*
- Chronic gastrointestinal blood loss typically causes **microcytic anemia** due to iron deficiency, not the macrocytic anemia seen here.
- While Crohn's can cause bleeding, the **elevated homocysteine with normal methylmalonic acid** is specific for **folate deficiency**, not blood loss.
*Inflammation of the ileum*
- **Ileal inflammation** is the most common location in Crohn disease and primarily affects the absorption of **vitamin B12** and **bile salts**.
- **Vitamin B12 deficiency** would cause elevated **both homocysteine and methylmalonic acid** levels, which contradicts the normal methylmalonic acid observed in this patient.
*Release of acute phase proteins*
- **Acute phase proteins** are markers of inflammation and contribute to **anemia of chronic disease**, which is typically **normocytic** or mildly **microcytic**.
- This mechanism does not explain the **macrocytic anemia** with the specific biochemical pattern of elevated homocysteine and normal methylmalonic acid, which indicates **folate deficiency**.
*Inflammation of the duodenum*
- The **duodenum** is the primary site for **iron absorption**, though it also participates in **folate absorption** along with the jejunum.
- However, inflammation here would more likely lead to **iron deficiency anemia** (microcytic), and duodenal involvement is **less common** in Crohn disease compared to terminal ileal or jejunal disease.
- The clinical picture is most consistent with **jejunal inflammation** causing isolated folate malabsorption.
Question 3: A 63-year-old man comes to the physician with a 4-week history of fatigue, crampy abdominal pain, watery diarrhea, and pain in his mouth and gums. He returned from a 2-week trip to the Dominican Republic 2 months ago. He has smoked one pack of cigarettes daily for 45 years. Examination shows three 1.5-cm, painful ulcers in the mouth. Abdominal examination shows mild tenderness to palpation in the right lower quadrant without guarding or rebound. His hemoglobin concentration is 11.2 g/dL, mean corpuscular volume is 75 fL, and leukocyte count is 11,900/mm³. Colonoscopy shows a cobblestone mucosa. A photomicrograph of a biopsy specimen is shown. Which of the following is the most likely diagnosis?
A. Behcet disease
B. Tropical sprue
C. Ulcerative colitis
D. Crohn disease (Correct Answer)
E. Whipple disease
Explanation: ***Crohn disease***
- The combination of **crampy abdominal pain**, **watery diarrhea**, **oral ulcers**, and **cobblestone mucosa** seen on colonoscopy strongly suggests Crohn disease. Crohn disease can affect any part of the gastrointestinal tract from mouth to anus, and oral manifestations like aphthous ulcers are common.
- The **microcytic anemia** (hemoglobin 11.2 g/dL, MCV 75 fL) is consistent with **chronic blood loss** and **iron malabsorption** often seen in Crohn disease. The elevated leukocyte count (11,900/mm³) indicates inflammation.
*Behcet disease*
- Behcet disease is characterized by recurrent **oral aphthous ulcers**, genital ulcers, and uveitis. While oral ulcers are present, the significant **gastrointestinal symptoms** (crampy abdominal pain, watery diarrhea, cobblestone mucosa) are not typical primary features of Behcet disease.
- Although it can rarely involve the GI tract, it typically doesn't present with extensive bowel involvement resembling inflammatory bowel disease to this degree, nor does it typically cause microcytic anemia from chronic GI blood loss.
*Tropical sprue*
- Tropical sprue typically presents with chronic **malabsorption**, foul-smelling diarrhea, and weight loss, occurring after travel to tropical regions. While the patient visited the Dominican Republic, the key findings of **oral ulcers** and **cobblestone mucosa** are not characteristic of tropical sprue.
- Tropical sprue is primarily a disease of the small intestine characterized by villous atrophy, not typically presenting with the "cobblestone" appearance associated with transmural inflammation seen in Crohn’s.
*Ulcerative colitis*
- Ulcerative colitis is characterized by continuous inflammation of the **colon and rectum**, typically presenting with bloody diarrhea and abdominal pain. While GI symptoms are present, the patient's **oral ulcers** and the finding of **cobblestone mucosa** strongly argue against ulcerative colitis.
- Ulcerative colitis affects only the colon and does not cause oral ulcers or skip lesions or transmural inflammation; the "cobblestone" appearance is indicative of deep fissures and ulcers separated by edematous mucosa, characteristic of Crohn disease.
*Whipple disease*
- Whipple disease is a rare systemic infection caused by *Tropheryma whipplei*, presenting with malabsorption, arthralgia, neurological symptoms, and lymphadenopathy. While GI symptoms like diarrhea and abdominal pain may occur, **oral ulcers** are not a typical feature, and the **colonoscopy findings** (cobblestone mucosa) are not characteristic of Whipple disease.
- Biopsy in Whipple disease would show **foamy macrophages** in the lamina propria that stain positive with periodic acid-Schiff (PAS), which is not indicated by the provided information.
Question 4: A 33-year-old man has a history of intermittent bloody diarrhea, tenesmus, fever, fatigue, and lower abdominal cramps for the past 2 weeks. On physical examination, he is lethargic and appears lean and pale. He has aphthous stomatitis, red congested conjunctiva, and tender swollen joints. At the doctor’s office, his pulse is 114/min, blood pressure is 102/76 mm Hg, respirations are 20/min, and his temperature is 39.4°C (102.9°F). There is vague lower abdominal tenderness and frank blood on rectal examination. Laboratory studies show:
Hemoglobin 7.6 g/dL
Hematocrit 33%
Total leucocyte count 22,000/mm3
Stool assay for C.difficile is negative
Abdominal X-ray shows no significant abnormality
He is symptomatically managed and referred to a gastroenterologist, who suggests a colonoscopy and contrast (barium) study for the diagnosis. Which of the following is the most likely combination of findings in his colonoscopy and barium study?
A. Colonoscopy: Multiple vascular malformations that resemble telangiectasias on the colon wall, Barium study: Normal
B. Colonoscopy: Patches of mucosal erosions with pseudomembrane formation, Barium study: Cobblestone appearance with strictures
C. Colonoscopy: Discontinuous transmural ‘skip lesions’ with aphthoid linear ulcers and transverse fissures, non-caseating granulomas, and strictures, Barium study: Cobblestone appearance with strictures
D. Colonoscopy: Normal, Barium study: Lead pipe colon appearance
E. Colonoscopy: Continuous ulcerated lesions involving the mucosa and submucosa, granular mucosa, crypt abscess, and pseudopolyps, Barium study: Lead pipe colon appearance (Correct Answer)
Explanation: ***Colonoscopy: Continuous ulcerated lesions involving the mucosa and submucosa granular mucosa, crypt abscess, and pseudopolyps, Barium study: Lead pipe colon appearance***
- The patient's symptoms (bloody diarrhea, tenesmus, fever, fatigue, weight loss, aphthous stomatitis, red congested conjunctiva, tender swollen joints, anemia, high WBC count) are highly suggestive of **Ulcerative Colitis (UC)**.
- **UC** on colonoscopy is characterized by **continuous mucosal and submucosal inflammation**, granular mucosa, crypt abscesses, and **pseudopolyps**. The barium study finding of a **"lead pipe" colon** is classic for long-standing UC due to loss of haustrations.
*Colonoscopy: Multiple vascular malformations that resemble telangiectasias on the colon wall, Barium study: Normal*
- **Angiodysplasia** presents with vascular malformations, but it typically causes painless lower GI bleeding, not the inflammatory symptoms described.
- The patient's severe systemic symptoms (fever, weight loss, anemia, high WBC) are inconsistent with angiodysplasia.
*Colonoscopy: Patches of mucosal erosions with pseudomembrane formation, Barium study: Cobblestone appearance with strictures*
- **Pseudomembrane formation** is characteristic of **_Clostridioides difficile_ infection**, which has been ruled out by the stool assay.
- While "cobblestone appearance" and strictures can be seen in inflammatory bowel disease, the pseudomembranes point away from UC or Crohn's.
*Colonoscopy: Discontinuous transmural ‘skip lesions’ with aphthoid linear ulcers and transverse fissures, non-caseating granulomas, and strictures, Barium study: Cobblestone appearance with strictures*
- This description is characteristic of **Crohn's disease**, which involves **discontinuous**, **transmural inflammation** with **skip lesions**, aphthoid ulcers, and non-caseating granulomas.
- While some symptoms overlap with UC, the involvement of mucocutaneous lesions and generalized systemic symptoms fits better with the continuous inflammation of UC than the patchy disease of Crohn's.
*Colonoscopy: Normal, Barium study: Lead pipe colon appearance*
- A **normal colonoscopy** would be inconsistent with the patient's severe symptoms of bloody diarrhea, anemia, and elevated inflammatory markers.
- A "lead pipe" colon indicates chronic inflammatory changes, which would undoubtedly be visible on colonoscopy.
Question 5: A 31-year-old woman comes to the emergency department because of a 4-day history of fever and diarrhea. She has abdominal cramps and frequent bowel movements of small quantities of stool with blood and mucus. She has had multiple similar episodes over the past 8 months. Her temperature is 38.1°C (100.6°F), pulse is 75/min, and blood pressure is 130/80 mm Hg. Bowel sounds are normal. The abdomen is soft. There is tenderness to palpation in the left lower quadrant with guarding and no rebound. She receives appropriate treatment and recovers. Two weeks later, colonoscopy shows polypoid growths flanked by linear ulcers. A colonic biopsy specimen shows mucosal edema with distorted crypts and inflammatory cells in the lamina propria. Which of the following is the most appropriate recommendation for this patient?
A. Obtain genetic studies now
B. Obtain barium follow-through radiography in 1 year
C. Obtain glutamate dehydrogenase antigen immunoassay now
D. Start annual magnetic resonance cholangiopancreatography screening in 10 years
E. Start annual colonoscopy starting in 8 years (Correct Answer)
Explanation: ***Start annual colonoscopy starting in 8 years***
- The patient's presentation with bloody diarrhea, abdominal cramps, and repetitive episodes is consistent with <b>inflammatory bowel disease (IBD)</b>, specifically likely <b>ulcerative colitis</b> given the left lower quadrant tenderness and colonic biopsy findings (distorted crypts, inflammatory cells in lamina propria).
- Patients with IBD, particularly ulcerative colitis affecting a significant portion of the colon and diagnosed at a younger age, are at increased risk for <b>colorectal cancer</b>. Annual colonoscopy screening is recommended 8–10 years after diagnosis for early detection and prevention.
*Obtain genetic studies now*
- While genetic factors play a role in IBD susceptibility, <b>genetic studies are not routinely indicated for diagnosis or management</b> of inflammatory bowel disease, nor do they guide current screening recommendations for colorectal cancer in IBD patients.
- Genetic studies would not provide immediate clinical benefit for this patient's acute symptoms or long-term management plan regarding cancer surveillance.
*Obtain barium follow-through radiography in 1 year*
- <b>Barium follow-through radiography</b> is primarily used to evaluate the small intestine, often in suspected Crohn's disease. This patient's symptoms and colonoscopy findings point towards colonic involvement, making this less appropriate.
- Furthermore, this imaging modality uses <b>ionizing radiation</b> and is less sensitive for detecting mucosal changes indicative of dysplasia or early cancer compared to colonoscopy.
*Obtain glutamate dehydrogenase antigen immunoassay now*
- <b>Glutamate dehydrogenase antigen immunoassay</b> is a test for <b><i>Clostridioides difficile</i> infection</b>. While C. difficile can cause severe diarrhea and colitis, the patient's history of recurrent episodes over 8 months and the specific colonoscopy findings (polypoid growths, linear ulcers, distorted crypts) are more characteristic of IBD.
- Although C. difficile infection can exacerbate IBD, it does not explain the chronic, recurrent nature of her illness or the long-term cancer surveillance needs.
*Start annual magnetic resonance cholangiopancreatography screening in 10 years*
- <b>MRCP screening</b> is used to monitor for <b>primary sclerosing cholangitis (PSC)</b>, a condition associated with IBD, particularly ulcerative colitis. However, PSC screening is performed <b>when clinically indicated</b> (e.g., elevated alkaline phosphatase, cholestatic symptoms), not as routine scheduled surveillance.
- This patient has no clinical features suggesting PSC at present, and there is no guideline recommending routine MRCP screening at a predetermined time interval for all IBD patients.
Question 6: A 25-year-old woman presents to the emergency department with fatigue and weakness. She states over the past 24 hours she has not felt like herself and has felt like she has no strength. The patient has no significant past medical history other than a single episode of blood-tinged diarrhea 1 week ago which resolved on its own. Her temperature is 99.4°F (37.4°C), blood pressure is 124/62 mmHg, pulse is 95/min, respirations are 29/min, and oxygen saturation is 95% on room air. Physical exam is notable for 2/5 strength of the lower extremities and decreased sensation in the lower extremities and finger tips. Which of the following is the best initial step in management?
A. IV immunoglobulin
B. Dexamethasone
C. Spirometry (Correct Answer)
D. Intubation
E. Pyridostigmine
Explanation: ***Spirometry***
- The patient's symptoms (fatigue, weakness, decreased strength, and sensation in extremities) following a gastrointestinal infection are highly suggestive of **Guillain-Barré Syndrome (GBS)**.
- **Spirometry** is the most critical initial step to assess respiratory function, as **respiratory muscle weakness** is the primary cause of morbidity and mortality in GBS.
*IV immunoglobulin*
- While **intravenous immunoglobulin (IVIG)** is a treatment for GBS, it is not the *initial* management step.
- The immediate priority in suspected GBS is to assess and stabilize the patient's respiratory status, not to initiate definitive treatment.
*Dexamethasone*
- **Corticosteroids** like dexamethasone have **not been shown to be effective** in treating GBS and may even prolong recovery in some cases.
- Their use is generally avoided in the management of GBS.
*Intubation*
- **Intubation** is indicated if spirometry reveals rapidly declining or severely compromised respiratory function, but it is not the *initial* step.
- An assessment of respiratory capacity via spirometry should precede intubation unless acute respiratory failure is immediately apparent.
*Pyridostigmine*
- **Pyridostigmine** is an anticholinesterase inhibitor used primarily for the symptomatic treatment of **myasthenia gravis**.
- It is not indicated for the management of GBS, which involves a different pathophysiological mechanism.
Question 7: A 19-year-old woman comes to the physician because of a 1-year history of severe abdominal pain, bloating, and episodic diarrhea. She also has a 10-kg (22-lb) weight loss over the past 10 months. Physical examination shows a mildly distended abdomen, diffuse abdominal tenderness, and multiple erythematous, tender nodules on the anterior aspect of both legs. There is a small draining lesion in the perianal region. Further evaluation of this patient's gastrointestinal tract is most likely to show which of the following findings?
A. Transmural inflammation (Correct Answer)
B. Melanosis coli
C. Villous atrophy
D. Crypt abscesses
E. No structural abnormalities
Explanation: **Transmural inflammation**
- The patient's symptoms (abdominal pain, bloating, diarrhea, weight loss) and extraintestinal manifestations (erythematous nodules, perianal lesion) are classic for **Crohn's disease**.
- A hallmark pathological feature of Crohn's disease is **transmural inflammation**, affecting all layers of the bowel wall, which can lead to complications like strictures, fistulas, and abscesses.
*Melanosis coli*
- This is a harmless condition characterized by **pigmentation of the colonic mucosa** due to chronic laxative use, particularly **anthraquinone laxatives**.
- It is not associated with inflammatory bowel disease or the systemic symptoms described.
*Villous atrophy*
- **Villous atrophy** is the flattening of the villi in the small intestine, most commonly seen in **celiac disease**.
- While celiac disease can cause malabsorption and gastrointestinal symptoms, the extraintestinal manifestations and perianal draining lesion are inconsistent with celiac disease.
*Crypt abscesses*
- **Crypt abscesses** are a characteristic histological finding in **ulcerative colitis**, which primarily affects the colon and rectum.
- While ulcerative colitis, like Crohn's, is an inflammatory bowel disease, the presence of transmural inflammation and perianal disease (fistulas/draining lesions) is more indicative of Crohn's.
*No structural abnormalities*
- The severe symptoms, significant weight loss, and presence of extraintestinal manifestations (erythema nodosum, perianal disease) strongly suggest an underlying structural and inflammatory pathology in the GI tract.
- **Irritable Bowel Syndrome (IBS)** typically presents with similar symptoms but lacks structural abnormalities and the systemic inflammatory signs seen here.
Question 8: A 37-year-old man with Crohn disease is admitted to the hospital because of acute small bowel obstruction. Endoscopy shows a stricture in the terminal ileum. The ileum is surgically resected after endoscopic balloon dilatation fails to relieve the obstruction. Three years later, he returns for a follow-up examination. He takes no medications. This patient is most likely to have which of the following physical exam findings?
A. Dry skin and keratomalacia
B. Weakness and ataxia (Correct Answer)
C. Hyperreflexia with tetany
D. Gingival swelling and bleeding
E. Pallor with koilonychia
Explanation: ***Weakness and ataxia***
- This patient with a history of **Crohn disease** and significant **ileal resection** is at high risk for **vitamin B12 deficiency** due to the removal of the primary site of absorption in the terminal ileum.
- **Vitamin B12 deficiency** can lead to subacute combined degeneration of the spinal cord, manifesting as **weakness**, **ataxia**, and **paresthesias**.
*Dry skin and keratomalacia*
- This presentation is indicative of **vitamin A deficiency**, which can occur in malabsorption but is less specific to ileal resection than B12 deficiency.
- While fat-soluble vitamins (A, D, E, K) are absorbed in the small intestine, severe isolated vitamin A deficiency causing keratomalacia is not the most likely primary finding after ileal resection.
*Hyperreflexia with tetany*
- These symptoms typically suggest **hypocalcemia** or **hypomagnesemia**, often due to vitamin D deficiency or malabsorption of minerals.
- Although possible with generalized malabsorption, it is not the most characteristic neurological complication following isolated ileal resection compared to vitamin B12 deficiency.
*Gingival swelling and bleeding*
- This is a hallmark of **scurvy**, caused by **vitamin C deficiency**, which is typically absorbed in the small intestine and does not correlate specifically with ileal resection.
- This would be a less likely complication given the specific history compared to micronutrient deficiencies related to terminal ileum function.
*Pallor with koilonychia*
- **Pallor** and **koilonychia (spoon nails)** are characteristic signs of **iron deficiency anemia**.
- While iron is absorbed in the duodenum and proximal jejunum, and anemia is common in Crohn disease, the specific neurological symptoms from B12 deficiency are generally more prominent after ileal resection.
Question 9: A 47-year-old man presents to his primary care physician complaining of pain and stiffness in his right index finger and left knee. The past medical history is remarkable for severe dandruff and an episode of apparent gout in the left 1st toe 6 months ago, which never resolved. The physical examination confirms dactylitis of the right index finger and several toes, as well as synovitis of the left knee. He is also noted to have pitting of his fingernails. Plain X-rays of his hand reveal erosions in the distal interphalangeal (DIP) joint and periarticular new bone formation. Which of the following is most consistent with these findings?
A. Psoriatic arthritis (Correct Answer)
B. Pseudogout
C. Osteoarthritis
D. Reactive arthritis
E. Rheumatoid arthritis
Explanation: ***Psoriatic arthritis***
- The constellation of **dactylitis**, **nail pitting**, involvement of both **DIP joints** with erosions, and a history of **psoriasis** (severe dandruff) is highly characteristic of psoriatic arthritis.
- The previous episode resembling gout and synovitis of the knee are also consistent, as psoriatic arthritis can mimic other arthropathies and affect various joints.
*Pseudogout*
- This condition is caused by **calcium pyrophosphate dihydrate crystal deposition** and typically presents as acute, severe joint pain, often in larger joints like the knee or wrist, but without dermatological or nail changes.
- While it can cause synovitis, it does not typically involve dactylitis, DIP erosions, nail pitting, or a history of psoriasis.
*Osteoarthritis*
- Characterized by **cartilage degeneration** and **new bone formation** (osteophytes), often in weight-bearing joints or DIP/PIP joints, but typically without the marked inflammatory signs like dactylitis or nail changes.
- While X-rays can show new bone formation, the presence of dactylitis, nail pitting, and psoriasis history rule out uncomplicated osteoarthritis.
*Reactive arthritis*
- This is an **acute, inflammatory arthropathy** that typically develops after a genitourinary or gastrointestinal infection.
- While it can present with dactylitis and oligoarthritis, it does not involve nail pitting or a history of psoriasis, and the initial trigger infection is usually identifiable.
*Rheumatoid arthritis*
- This is a **chronic autoimmune disease** primarily affecting smaller joints symmetrically, particularly the MCP and PIP joints, but typically sparing the DIP joints.
- It is not associated with psoriasis, nail pitting, and usually presents with periarticular osteopenia rather than significant new bone formation on X-ray.
Question 10: An otherwise healthy 27-year-old man presents to his dermatologist because of a rash over his knees. The rash has been present for 5 weeks and is moderately itchy. Physical examination reveals erythematous plaques covered with silvery scales over the extensor surface of the knees as shown in the image. Which of the following is the best initial step in the management of this patient’s condition?
A. Oral cyclosporine
B. Oral methotrexate
C. Skin biopsy
D. Topical corticosteroids and/or topical vitamin D analog (Correct Answer)
E. Oral corticosteroids
Explanation: ***Topical corticosteroids and/or topical vitamin D analog***
- The patient's presentation with **erythematous plaques** and **silvery scales** on the extensor surfaces of the knees is classic for **plaque psoriasis**.
- For localized, mild-to-moderate plaque psoriasis, **topical corticosteroids** and/or **topical vitamin D analogs** are the first-line treatment due to their effectiveness and favorable side-effect profile.
*Oral cyclosporine*
- **Cyclosporine** is an immunosuppressant typically reserved for **severe, refractory psoriasis** due to its potential for significant side effects, including **nephrotoxicity** and **hypertension**.
- It is not indicated as an initial step for localized psoriasis, especially in an otherwise healthy patient.
*Oral methotrexate*
- **Methotrexate** is a systemic agent used for **moderate to severe psoriasis**, particularly when topical treatments are insufficient or the disease significantly impacts quality of life.
- Its use requires monitoring for potential adverse effects such as **hepatotoxicity** and **myelosuppression**, making it unsuitable as an initial treatment for localized disease.
*Skin biopsy*
- While a **skin biopsy** can confirm the diagnosis of psoriasis, the clinical presentation in this case is highly characteristic, making a biopsy **unnecessary as an initial step** for management initiation.
- A biopsy might be considered if the diagnosis is ambiguous or if the lesions are unresponsive to initial therapy.
*Oral corticosteroids*
- **Oral corticosteroids** are generally **contraindicated** in psoriasis due to the risk of **rebound flares** and potential exacerbation of the condition upon withdrawal.
- They may be used in specific, severe cases but are not suitable as a routine initial treatment for typical plaque psoriasis.