A 45-year-old man presents to the emergency department for sudden pain in his foot. The patient states that when he woke up, he experienced severe pain in his right great toe. The patient’s wife immediately brought him to the emergency department. The patient has a past medical history of diabetes mellitus, obesity, and hypertension and is currently taking insulin, metformin, lisinopril, and ibuprofen. The patient is a current smoker and smokes 2 packs per day. He also drinks 3 glasses of whiskey every night. The patient is started on IV fluids and corticosteroids. His blood pressure, taken at the end of this visit, is 175/95 mmHg. As the patient’s symptoms improve, he asks how he can avoid having these symptoms again in the future. Which of the following is the best initial intervention in preventing a future episode of this patient’s condition?
Q362
A 25-year-old woman presents with abdominal pain and discomfort for the past 3 days. She was diagnosed with irritable bowel syndrome (IBS) a couple of years ago, managed until recently with imipramine, psyllium, and loperamide. 5 days ago, because she had developed alternating diarrhea and constipation, bloating, and abdominal pain on her medication, she was started on alosetron. Her current temperature is 39.0°C (102.2°F), the heart rate is 115/min, the blood pressure is 90/60 mm Hg and the respiratory rate is 22/min. Abdominal examination shows diffuse tenderness to palpation with guarding but no rebound. Bowel sounds are hypoactive on auscultation. A fecal occult blood test is positive and laboratory tests show her white cell count to be 15,800/µL. Arterial blood gas (ABG) analysis reveals a metabolic acidosis. Which of the following is the most likely diagnosis in this patient?
Q363
A 56-year-old woman presents to the ER with 12 hours of right flank pain that radiates from her groin down her inner thigh. The patient complains of dysuria, hematuria, and reports of "passing gravel" when urinating. She was diagnosed with gout and hypertension 5 years ago. Physical examination is unremarkable. The emergency department team orders urinalysis and a CT scan that shows a mild dilation of the right ureter associated with multiple small stones of low Hounsfield unit values (HU). Which of the following findings is most likely to appear in the urinalysis of this patient?
Q364
A 41-year-old woman is brought to the emergency department with the acute-onset of severe abdominal pain for the past 2 hours. She has a history of frequent episodes of vague abdominal pain, but they have never been this severe. Every time she has had pain, it would resolve after eating a meal. Her past medical history is otherwise insignificant. Her vital signs include: blood pressure 121/77 mm Hg, pulse 91/min, respiratory rate 21/min, and temperature 37°C (98.6°F). On examination, her abdomen is flat and rigid. Which of the following is the next best step in evaluating this patient’s discomfort and stomach pain by physical exam?
Q365
A 26-year-old white man comes to the physician because of increasing generalized fatigue for 6 months. He has been unable to work out at the gym during this period. He has also had cramping lower abdominal pain and diarrhea for the past 5 weeks that is occasionally bloody. His father was diagnosed with colon cancer at the age of 65. He has smoked half a pack of cigarettes daily for the past 10 years. He drinks 1–2 beers on social occasions. His temperature is 37.3°C (99.1°F), pulse is 88/min, and blood pressure is 116/74 mm Hg. Physical examination shows dry mucous membranes. The abdomen is soft and nondistended with slight tenderness to palpation over the lower quadrants bilaterally. Rectal examination shows stool mixed with blood. His hemoglobin concentration is 13.5 g/dL, leukocyte count is 7,500/mm3, and platelet count is 480,000/mm3. Urinalysis is within normal limits. Which of the following is the most appropriate next step in management?
Q366
A previously healthy 20-year-old woman comes to the physician because of recurrent abdominal cramps, bloating, and diarrhea for 4 months. She describes her stools as greasy, foul-smelling, and difficult to flush. During this time she has had a 6-kg (13.2-lb) weight loss. She has no personal or family history of serious illness. Physical examination shows pallor and cheilitis. Laboratory studies show a hemoglobin concentration of 11 g/dL. Serum concentrations of electrolytes, urea nitrogen, and creatinine are within the reference range. Test of the stool for occult blood is negative and stool microscopy reveals no pathogens and no leukocytes. Analysis of a 24-hour stool sample shows 12 g of fat. The patient is asked to consume 25 g of d-xylose. Five hours later, its concentration is measured in urine at 2 g (N = > 4 g/5 h). The test is repeated after a two-week course of rifaximin, but the urinary concentration of d-xylose remains the same. Which of the following is the most likely diagnosis?
Q367
A 33-year-old woman presents to her primary care physician for gradually worsening pain in both wrists that began several months ago. The pain originally did not bother her, but it has recently begun to affect her daily functioning. She states that the early morning stiffness in her hands is severe and has made it difficult to tend to her rose garden. She occasionally takes ibuprofen for the pain, but she says this does not really help. Her medical history is significant for diabetes mellitus and major depressive disorder. She is currently taking insulin, sertraline, and a daily multivitamin. The vital signs include: blood pressure 126/84 mm Hg, heart rate 82/min, and temperature 37.0°C (98.6°F). On physical exam, her wrists and metacarpophalangeal joints are swollen, tender, erythematous, and warm to the touch. There are no nodules or vasculitic lesions. Which of the following antibodies would be most specific to this patient’s condition?
Q368
A 65-year-old woman is brought to the emergency department by her husband who found her lying unconscious at home. He says that the patient has been complaining of progressively worsening weakness and confusion for the past week. Her past medical history is significant for hypertension, systemic lupus erythematosus, and trigeminal neuralgia. Her medications include metoprolol, valsartan, prednisone, and carbamazepine. On admission, blood pressure is 130/70 mm Hg, pulse rate is 100 /min, respiratory rate is 17/min, and temperature is 36.5°C (97.7ºF). She regained consciousness while on the way to the hospital but is still drowsy and disoriented. Physical examination is normal. Finger-stick glucose level is 110 mg/dl. Other laboratory studies show:
Na+ 120 mEq/L (136—145 mEq/L)
K+ 3.5 mEq/L (3.5—5.0 mEq/L)
CI- 107 mEq/L (95—105 mEq/L)
Creatinine 0.8 mg/dL (0.6—1.2 mg/dL)
Serum osmolality 250 mOsm/kg (275—295 mOsm/kg)
Urine Na+ 70 mEq/L
Urine osmolality 350 mOsm/kg
She is admitted to the hospital for further management. Which of the following is the next best step in the management of this patient's condition?
Q369
A 55-year-old woman presents with fatigue and flu-like symptoms. She says her symptoms started 5 days ago with a low-grade fever and myalgia, which have not improved. For the past 4 days, she has also had chills, sore throat, and rhinorrhea. She works as a kindergarten teacher and says several children in her class have had similar symptoms. Her past medical history is significant for depression managed with escitalopram, and dysmenorrhea. A review of systems is significant for general fatigue for the past 5 months. Her vital signs include: temperature 38.5°C (101.3°F), pulse 99/min, blood pressure 115/75 mm Hg, and respiratory rate 22/min. Physical examination reveals pallor of the mucous membranes. Initial laboratory findings are significant for the following:
Hematocrit 24.5%
Hemoglobin 11.0 g/dL
Platelet Count 215,000/mm3
Mean corpuscular volume (MCV) 82 fL
Red cell distribution width (RDW) 10.5%
Which of the following is the best next diagnostic test in this patient?
Q370
A 58-year-old department store manager comes to his doctor’s office complaining that he had recently been waking up in the middle of the night with abdominal pain. This has happened several nights a week in the past month. He has also been experiencing occasional discomfort in the afternoon. The patient's appetite has suffered as a result of the pain he was experiencing. His clothes hang on him loosely. The patient does not take any prescription or over the counter medications. The remainder of the patient’s history and physical exam is completely normal. The doctor refers the patient to a gastroenterologist for a stomach acid test and an upper gastrointestinal endoscopy which revealed that this patient is a heavy acid producer and has a gastric peptic ulcer. This ulcer is most likely found in which part of the stomach?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 361: A 45-year-old man presents to the emergency department for sudden pain in his foot. The patient states that when he woke up, he experienced severe pain in his right great toe. The patient’s wife immediately brought him to the emergency department. The patient has a past medical history of diabetes mellitus, obesity, and hypertension and is currently taking insulin, metformin, lisinopril, and ibuprofen. The patient is a current smoker and smokes 2 packs per day. He also drinks 3 glasses of whiskey every night. The patient is started on IV fluids and corticosteroids. His blood pressure, taken at the end of this visit, is 175/95 mmHg. As the patient’s symptoms improve, he asks how he can avoid having these symptoms again in the future. Which of the following is the best initial intervention in preventing a future episode of this patient’s condition?
A. Probenecid
B. Allopurinol
C. Hydrochlorothiazide
D. Lifestyle measures (Correct Answer)
E. Niacin
Explanation: ***Lifestyle measures***
- **Lifestyle changes** are the **first-line intervention** for **gout** prevention, addressing risk factors like **obesity**, **alcohol consumption**, and certain dietary habits.
- These measures include **weight loss**, reducing **alcohol intake** (especially beer and spirits), avoiding **purine-rich foods**, and increasing **hydration**.
*Probenecid*
- **Probenecid** is a **uricosuric agent** that increases the excretion of uric acid in the urine.
- It is typically used for gout prevention in patients who are **under-excreters of uric acid** and have **normal kidney function**, after lifestyle measures have failed or are insufficient.
*Allopurinol*
- **Allopurinol** is a **xanthine oxidase inhibitor** that reduces the production of uric acid.
- It is often considered in patients with **recurrent gout attacks**, **tophi**, or **renal stones**, but initial management should still focus on lifestyle modifications.
*Hydrochlorothiazide*
- **Hydrochlorothiazide** is a **thiazide diuretic** often used for **hypertension**.
- It can **increase serum uric acid levels** and potentially worsen gout, so it would not be a preventative measure.
*Niacin*
- **Niacin** (vitamin B3) is sometimes used to **lower cholesterol**, but it can also **increase uric acid levels** and thus precipitate or worsen gout.
- Therefore, it is **contraindicated** in gout management and would not be an appropriate preventative intervention.
Question 362: A 25-year-old woman presents with abdominal pain and discomfort for the past 3 days. She was diagnosed with irritable bowel syndrome (IBS) a couple of years ago, managed until recently with imipramine, psyllium, and loperamide. 5 days ago, because she had developed alternating diarrhea and constipation, bloating, and abdominal pain on her medication, she was started on alosetron. Her current temperature is 39.0°C (102.2°F), the heart rate is 115/min, the blood pressure is 90/60 mm Hg and the respiratory rate is 22/min. Abdominal examination shows diffuse tenderness to palpation with guarding but no rebound. Bowel sounds are hypoactive on auscultation. A fecal occult blood test is positive and laboratory tests show her white cell count to be 15,800/µL. Arterial blood gas (ABG) analysis reveals a metabolic acidosis. Which of the following is the most likely diagnosis in this patient?
A. Perforated duodenal ulcer
B. Pseudomembranous colitis
C. Appendicitis
D. Crohn’s disease
E. Ischemic colitis (Correct Answer)
Explanation: ***Ischemic colitis***
- The patient's presentation with **abdominal pain**, **fever**, **tachycardia**, **hypotension**, **diffuse tenderness with guarding**, **positive fecal occult blood**, **leukocytosis**, and **metabolic acidosis** after starting **alosetron** is highly suggestive of ischemic colitis. Alosetron, a 5-HT3 antagonist, can cause severe constipation and, rarely, **ischemic colitis**.
- The **hypoactive bowel sounds** and signs of **systemic inflammatory response** (fever, tachycardia, leukocytosis) further support a diagnosis of ischemic bowel compromise leading to colitis.
*Perforated duodenal ulcer*
- A perforated duodenal ulcer typically presents with sudden onset, **severe, sharp epigastric pain** that rapidly generalizes, often with a rigid, board-like abdomen and **rebound tenderness**, which is not seen here.
- While it can cause peritonitis and systemic signs, the history of recent medication change and more diffuse abdominal tenderness points away from an isolated perforation.
*Pseudomembranous colitis*
- Pseudomembranous colitis is primarily associated with **Clostridium difficile infection**, often following antibiotic use, and typically presents with severe watery diarrhea, not necessarily with a metabolic acidosis or overt signs of ischemia as seen in this case.
- While it can cause abdominal pain and systemic symptoms, the acute onset with severe tenderness and shock-like picture makes ischemic colitis more likely given the drug history.
*Appendicitis*
- Appendicitis typically presents with **periumbilical pain** that migrates to the **right lower quadrant**, often with localized tenderness at McBurney's point and rebound tenderness.
- The patient's **diffuse abdominal tenderness**, associated with such severe systemic symptoms and a history of specific medication use, is inconsistent with typical appendicitis.
*Crohn’s disease*
- Crohn's disease is a **chronic inflammatory bowel condition** characterized by transmural inflammation, often with intermittent abdominal pain, diarrhea, and weight loss, but it is less likely to present acutely with such severe, systemic signs and shock-like features without a clear exacerbating factor like acute ischemia.
- While Crohn's can cause complications like strictures or fistulas, an acute presentation resembling ischemic colitis with a clear provoking drug history is less common for an initial severe flare.
Question 363: A 56-year-old woman presents to the ER with 12 hours of right flank pain that radiates from her groin down her inner thigh. The patient complains of dysuria, hematuria, and reports of "passing gravel" when urinating. She was diagnosed with gout and hypertension 5 years ago. Physical examination is unremarkable. The emergency department team orders urinalysis and a CT scan that shows a mild dilation of the right ureter associated with multiple small stones of low Hounsfield unit values (HU). Which of the following findings is most likely to appear in the urinalysis of this patient?
A. Acidic urine (Correct Answer)
B. Alkaline urine
C. Positive leukocyte esterase
D. Nitrites
E. Low specific gravity
Explanation: ***Acidic urine***
- The patient has gout, a risk factor for **uric acid stones**. **Uric acid stones** are radiolucent on X-ray and have low Hounsfield units on CT, consistent with the findings.
- Formation of uric acid stones is favored in an **acidic urine environment** (pH < 5.5), where uric acid is less soluble.
*Alkaline urine*
- **Alkaline urine** (pH > 7.0) is typically associated with **struvite stones** (magnesium ammonium phosphate), which form in the presence of urinary tract infections with urea-splitting organisms.
- The patient's presentation and CT findings are not suggestive of struvite stones or infection as the primary cause.
*Positive leukocyte esterase*
- **Leukocyte esterase** indicates the presence of white blood cells in the urine, suggesting a **urinary tract infection (UTI)**.
- While kidney stones can predispose to UTIs, the patient's presentation focuses on colic pain and stone passage, and there are no direct indications of active infection, making a UTI less likely to be the primary finding compared to acidic urine with uric acid stones.
*Nitrites*
- **Nitrites** in urine are a strong indicator of a **urinary tract infection (UTI)**, as many gram-negative bacteria convert nitrates to nitrites.
- Similar to positive leukocyte esterase, while a UTI is possible, the primary diagnostic features in this scenario point towards uric acid stones.
*Low specific gravity*
- **Low specific gravity** suggests dilute urine, which is generally protective against stone formation as it reduces the concentration of stone-forming substances.
- In a patient with active stone formation and symptoms of ureteral obstruction, the urine specific gravity may be normal or even elevated due to dehydration or concentrated urine, not low.
Question 364: A 41-year-old woman is brought to the emergency department with the acute-onset of severe abdominal pain for the past 2 hours. She has a history of frequent episodes of vague abdominal pain, but they have never been this severe. Every time she has had pain, it would resolve after eating a meal. Her past medical history is otherwise insignificant. Her vital signs include: blood pressure 121/77 mm Hg, pulse 91/min, respiratory rate 21/min, and temperature 37°C (98.6°F). On examination, her abdomen is flat and rigid. Which of the following is the next best step in evaluating this patient’s discomfort and stomach pain by physical exam?
A. Auscultate the abdomen (Correct Answer)
B. Elicit shifting dullness of the abdomen
C. Perform light palpation at the point of maximal pain
D. Attempt to perform a deep, slow palpation with quick release
E. Percuss the point of maximal pain
Explanation: ***Auscultate the abdomen***
- Auscultation is typically performed first in an abdominal exam to assess **bowel sounds** and identify any bruits, as palpation and percussion can alter bowel sound characteristics.
- While the patient has **peritonitis (rigid abdomen)**, initial auscultation is still the logical starting point for a comprehensive physical examination.
*Elicit shifting dullness of the abdomen*
- **Shifting dullness** is used to detect **ascites**, which is not the primary concern given the acute onset of severe pain and rigid abdomen.
- This maneuver typically comes later in the abdominal examination, after initial auscultation and palpation.
*Perform light palpation at the point of maximal pain*
- Given the patient's **rigid abdomen**, suggesting peritonitis, performing palpation (even light) at the point of maximal pain could cause significant discomfort and is secondary to initial auscultation in the *sequence* of physical exam.
- While palpation is crucial, the standard order in an abdominal exam begins with auscultation to ensure unchanged bowel sounds.
*Attempt to perform a deep, slow palpation with quick release*
- This describes evaluating for **rebound tenderness**, a sign of peritonitis, which is indeed suggested by the rigid abdomen.
- However, just like light palpation, this maneuver is performed *after* auscultation and is likely to cause significant pain in a patient with a rigid abdomen, making it not the very next best step.
*Percuss the point of maximal pain*
- Percussion is typically used to assess for **gas, fluid, or organ size/tenderness**, but it is performed after auscultation and before deep palpation in a standard abdominal exam.
- In a patient with a **rigid abdomen**, percussion can also elicit severe pain, and it does not precede auscultation in the examination sequence.
Question 365: A 26-year-old white man comes to the physician because of increasing generalized fatigue for 6 months. He has been unable to work out at the gym during this period. He has also had cramping lower abdominal pain and diarrhea for the past 5 weeks that is occasionally bloody. His father was diagnosed with colon cancer at the age of 65. He has smoked half a pack of cigarettes daily for the past 10 years. He drinks 1–2 beers on social occasions. His temperature is 37.3°C (99.1°F), pulse is 88/min, and blood pressure is 116/74 mm Hg. Physical examination shows dry mucous membranes. The abdomen is soft and nondistended with slight tenderness to palpation over the lower quadrants bilaterally. Rectal examination shows stool mixed with blood. His hemoglobin concentration is 13.5 g/dL, leukocyte count is 7,500/mm3, and platelet count is 480,000/mm3. Urinalysis is within normal limits. Which of the following is the most appropriate next step in management?
A. D-xylose absorption test
B. CT scan of the abdomen and pelvis with contrast
C. Capsule endoscopy
D. Colonoscopy (Correct Answer)
E. Flexible sigmoidoscopy
Explanation: ***Colonoscopy***
- The patient presents with **bloody diarrhea** and **lower abdominal pain**, which are classic symptoms of inflammatory bowel disease (IBD), particularly **Crohn's disease** or **ulcerative colitis**. A colonoscopy allows for direct visualization of the colonic and terminal ileal mucosa, **biopsy collection** for histological confirmation, and assessment of disease extent and severity.
- While the patient's hemoglobin is currently normal, the presence of bloody stools indicates potential ongoing blood loss, and the history of fatigue suggests chronic inflammation. **Colonoscopy is the gold standard** for diagnosing and differentiating types of IBD.
*D-xylose absorption test*
- This test is used to assess **small bowel mucosal function** and carbohydrate absorption, typically in cases of suspected malabsorption like **celiac disease**.
- While malabsorption can cause fatigue, the patient's primary symptoms of bloody diarrhea and abdominal pain are not typical for isolated malabsorption, and a d-xylose test would not identify the source of bleeding.
*CT scan of the abdomen and pelvis with contrast*
- A CT scan can identify **extraintestinal manifestations** of IBD, abscesses, or bowel wall thickening, but it is **less sensitive** than colonoscopy for direct mucosal evaluation and cannot obtain biopsies for definitive diagnosis.
- It might be considered after colonoscopy for assessing transmural involvement or complications but is not the initial diagnostic step for primary luminal symptoms.
*Capsule endoscopy*
- Capsule endoscopy is primarily used to evaluate the **small bowel** for lesions beyond the reach of standard upper endoscopy and colonoscopy, such as obscure GI bleeding or suspected Crohn's disease confined to the small bowel.
- Given the patient's symptoms of **lower abdominal pain** and bloody diarrhea, the pathology is likely in the colon or terminal ileum, making colonoscopy more appropriate for initial evaluation. A capsule endoscopy does not visualize the colon.
*Flexible sigmoidoscopy*
- A flexible sigmoidoscopy visualizes the **rectum and a portion of the sigmoid colon**, which might be affected in ulcerative colitis.
- However, it would miss lesions in the more proximal colon or terminal ileum, which are common sites for Crohn's disease and some forms of ulcerative colitis, thus potentially leading to an incomplete diagnosis.
Question 366: A previously healthy 20-year-old woman comes to the physician because of recurrent abdominal cramps, bloating, and diarrhea for 4 months. She describes her stools as greasy, foul-smelling, and difficult to flush. During this time she has had a 6-kg (13.2-lb) weight loss. She has no personal or family history of serious illness. Physical examination shows pallor and cheilitis. Laboratory studies show a hemoglobin concentration of 11 g/dL. Serum concentrations of electrolytes, urea nitrogen, and creatinine are within the reference range. Test of the stool for occult blood is negative and stool microscopy reveals no pathogens and no leukocytes. Analysis of a 24-hour stool sample shows 12 g of fat. The patient is asked to consume 25 g of d-xylose. Five hours later, its concentration is measured in urine at 2 g (N = > 4 g/5 h). The test is repeated after a two-week course of rifaximin, but the urinary concentration of d-xylose remains the same. Which of the following is the most likely diagnosis?
A. Exocrine pancreatic insufficiency
B. Bacterial overgrowth in the small intestine
C. Tropheryma whipplei infection
D. Hypersensitivity to gliadin (Correct Answer)
E. Lactose intolerance
Explanation: ***Hypersensitivity to gliadin***
* The patient's symptoms (greasy, foul-smelling stools, weight loss, abdominal cramps, bloating, diarrhea, pallor, cheilitis, iron-deficiency anemia) are highly suggestive of **malabsorption**.
* The **impaired d-xylose absorption** that does not improve after antibiotics points to an intrinsic small bowel mucosal defect rather than bacterial overgrowth, making celiac disease (hypersensitivity to gliadin) the most likely diagnosis.
*Exocrine pancreatic insufficiency*
* While it causes **steatorrhea** and malabsorption, it typically presents with normal d-xylose absorption because **d-xylose is a monosaccharide that is absorbed directly by the intestinal mucosa without requiring pancreatic enzymes**.
* The normal function of the small intestinal mucosa would allow for adequate d-xylose absorption.
*Bacterial overgrowth in the small intestine*
* Symptoms can mimic malabsorption, and d-xylose absorption may be impaired due to bacterial consumption.
* However, the patient's d-xylose test did not improve after a course of **rifaximin**, which is an antibiotic effective against bacterial overgrowth.
*Tropheryma whipplei infection*
* Whipple's disease can cause malabsorption, **steatorrhea**, and abdominal symptoms similar to those described.
* However, it also commonly presents with **arthralgia, lymphadenopathy, and neurological symptoms**, which are absent in this patient.
*Lactose intolerance*
* This condition primarily causes bloating, cramps, and diarrhea, but typically does not lead to **significant weight loss** or **steatorrhea (greasy stools)**.
* D-xylose absorption would also be expected to be normal because it is a **monosaccharide** that is absorbed directly, unlike lactose which requires lactase.
Question 367: A 33-year-old woman presents to her primary care physician for gradually worsening pain in both wrists that began several months ago. The pain originally did not bother her, but it has recently begun to affect her daily functioning. She states that the early morning stiffness in her hands is severe and has made it difficult to tend to her rose garden. She occasionally takes ibuprofen for the pain, but she says this does not really help. Her medical history is significant for diabetes mellitus and major depressive disorder. She is currently taking insulin, sertraline, and a daily multivitamin. The vital signs include: blood pressure 126/84 mm Hg, heart rate 82/min, and temperature 37.0°C (98.6°F). On physical exam, her wrists and metacarpophalangeal joints are swollen, tender, erythematous, and warm to the touch. There are no nodules or vasculitic lesions. Which of the following antibodies would be most specific to this patient’s condition?
A. c-ANCA
B. Anti-Ro
C. Anti-Scl-70
D. Anti-cyclic citrullinated peptide (Correct Answer)
E. Rheumatoid factor
Explanation: ***Anti-cyclic citrullinated peptide***
- **Anti-cyclic citrullinated peptide (anti-CCP)** antibodies are highly specific for **rheumatoid arthritis (RA)** and are often present early in the disease course.
- The patient's presentation with **symmetric polyarthritis**, particularly affecting the **wrists and metacarpophalangeal joints**, with severe **morning stiffness**, is classic for RA.
*c-ANCA*
- **c-ANCA (cytoplasmic antineutrophil cytoplasmic antibodies)** are primarily associated with **granulomatosis with polyangiitis (Wegener's)**, a systemic vasculitis.
- This condition typically presents with symptoms such as **upper and lower respiratory tract involvement**, **renal disease**, and constitutional symptoms, which are not described here.
*Anti-Ro*
- **Anti-Ro (SS-A)** antibodies are strongly associated with **Sjögren's syndrome**, a chronic autoimmune disease characterized by dry eyes and mouth, and also with **systemic lupus erythematosus (SLE)**.
- While Sjögren's can present with arthritis, the prominent joint inflammation and morning stiffness described are more characteristic of rheumatoid arthritis.
*Anti-Scl-70*
- **Anti-Scl-70 (anti-topoisomerase I)** antibodies are highly specific for **systemic sclerosis (scleroderma)**, particularly the diffuse cutaneous form.
- Scleroderma presents with **skin thickening**, **Raynaud's phenomenon**, and potential involvement of internal organs like the lungs and esophagus, which are absent in this patient's presentation.
*Rheumatoid factor*
- **Rheumatoid factor (RF)** is often positive in **rheumatoid arthritis**, but it is less specific than anti-CCP antibodies.
- RF can also be elevated in other autoimmune diseases, chronic infections, and even in healthy individuals, making it a less specific diagnostic marker.
Question 368: A 65-year-old woman is brought to the emergency department by her husband who found her lying unconscious at home. He says that the patient has been complaining of progressively worsening weakness and confusion for the past week. Her past medical history is significant for hypertension, systemic lupus erythematosus, and trigeminal neuralgia. Her medications include metoprolol, valsartan, prednisone, and carbamazepine. On admission, blood pressure is 130/70 mm Hg, pulse rate is 100 /min, respiratory rate is 17/min, and temperature is 36.5°C (97.7ºF). She regained consciousness while on the way to the hospital but is still drowsy and disoriented. Physical examination is normal. Finger-stick glucose level is 110 mg/dl. Other laboratory studies show:
Na+ 120 mEq/L (136—145 mEq/L)
K+ 3.5 mEq/L (3.5—5.0 mEq/L)
CI- 107 mEq/L (95—105 mEq/L)
Creatinine 0.8 mg/dL (0.6—1.2 mg/dL)
Serum osmolality 250 mOsm/kg (275—295 mOsm/kg)
Urine Na+ 70 mEq/L
Urine osmolality 350 mOsm/kg
She is admitted to the hospital for further management. Which of the following is the next best step in the management of this patient's condition?
A. Rapid resuscitation with hypertonic saline (Correct Answer)
B. Fluid restriction
C. Tolvaptan
D. Lithium
E. Desmopressin
Explanation: **Rapid resuscitation with hypertonic saline**
- The patient presents with **severe hyponatremia** (120 mEq/L) and neurological symptoms (drowsiness, disorientation, history of unconsciousness), indicating a need for **urgent correction** to prevent cerebral edema.
- **Hypertonic saline** (e.g., 3%) is indicated for severe symptomatic hyponatremia to rapidly increase serum sodium levels and reduce brain swelling.
*Fluid restriction*
- **Fluid restriction** is a conservative measure appropriate for **mild to moderate asymptomatic hyponatremia** or as an adjunct in SIADH management once severe symptoms are controlled.
- It would be too slow to address the patient's acute neurological symptoms and severe hyponatremia, potentially delaying critical treatment.
*Tolvaptan*
- **Tolvaptan** is a **vasopressin receptor antagonist** used in the treatment of **euvolemic or hypervolemic hyponatremia**, often in the context of SIADH.
- Its use is generally reserved for patients who have not responded to fluid restriction and is **contraindicated** in patients with severe symptoms or to rapidly correct severe hyponatremia due to the risk of overly rapid correction and osmotic demyelination syndrome.
*Lithium*
- **Lithium** is primarily used as a **mood stabilizer** in psychiatric conditions, particularly bipolar disorder.
- It can cause **nephrogenic diabetes insipidus** as a side effect and is not a treatment for hyponatremia.
*Desmopressin*
- **Desmopressin** is a synthetic analog of **antidiuretic hormone (ADH)** and is used to treat **diabetes insipidus** or nocturnal enuresis.
- Administering desmopressin would **worsen hyponatremia** by promoting water reabsorption, making it an inappropriate choice for this patient.
Question 369: A 55-year-old woman presents with fatigue and flu-like symptoms. She says her symptoms started 5 days ago with a low-grade fever and myalgia, which have not improved. For the past 4 days, she has also had chills, sore throat, and rhinorrhea. She works as a kindergarten teacher and says several children in her class have had similar symptoms. Her past medical history is significant for depression managed with escitalopram, and dysmenorrhea. A review of systems is significant for general fatigue for the past 5 months. Her vital signs include: temperature 38.5°C (101.3°F), pulse 99/min, blood pressure 115/75 mm Hg, and respiratory rate 22/min. Physical examination reveals pallor of the mucous membranes. Initial laboratory findings are significant for the following:
Hematocrit 24.5%
Hemoglobin 11.0 g/dL
Platelet Count 215,000/mm3
Mean corpuscular volume (MCV) 82 fL
Red cell distribution width (RDW) 10.5%
Which of the following is the best next diagnostic test in this patient?
A. Serum iron level
B. Serum ferritin level
C. Reticulocyte count (Correct Answer)
D. Hemoglobin electrophoresis
E. Serum folate level
Explanation: ***Reticulocyte count***
- The patient presents with **fatigue, pallor, and anemia (Hb 11.0 g/dL)**. Given the acute illness (flu-like symptoms) and underlying chronic fatigue, a **reticulocyte count** helps determine if the bone marrow is adequately responding to the anemia.
- A low or inappropriately normal reticulocyte count in the setting of anemia suggests a problem with **red blood cell production** (e.g., marrow suppression, nutritional deficiency), while a high count would suggest hemolysis or acute blood loss.
*Serum iron level*
- While iron-deficiency anemia is common, the patient's **MCV of 82 fL** is within the normal range, suggesting a **normocytic anemia**, which makes iron deficiency less likely as a primary cause without further investigation.
- Furthermore, **serum iron levels** can be acutely affected by inflammation or infection, making them unreliable in the presence of acute flu-like symptoms.
*Serum ferritin level*
- **Ferritin** is an acute-phase reactant; therefore, in the context of an acute infection or inflammation (flu-like symptoms, fever), a **serum ferritin level** can be falsely elevated, masking true iron deficiency, which makes it less reliable as the *best first* diagnostic test in this scenario.
- While low ferritin is diagnostic of iron deficiency, a normal or even elevated ferritin does not rule it out in the presence of inflammation, thus complicating interpretation.
*Hemoglobin electrophoresis*
- **Hemoglobin electrophoresis** is used to diagnose **hemoglobinopathies** like **sickle cell disease** or **thalassemia**. There are no clinical or laboratory findings (e.g., microcytosis, prior family history of hemoglobinopathies) to suggest this as the most appropriate initial investigation for this patient's acute presentation.
- The patient's **normocytic anemia** (MCV 82 fL) further argues against typical thalassemia presentations, which are usually microcytic.
*Serum folate level*
- **Folate deficiency** typically causes a **macrocytic anemia** (elevated MCV), which is not observed in this patient (MCV 82 fL being normocytic).
- There are no specific risk factors or clinical signs presented that would clearly point towards folate deficiency as the primary cause for her anemia.
Question 370: A 58-year-old department store manager comes to his doctor’s office complaining that he had recently been waking up in the middle of the night with abdominal pain. This has happened several nights a week in the past month. He has also been experiencing occasional discomfort in the afternoon. The patient's appetite has suffered as a result of the pain he was experiencing. His clothes hang on him loosely. The patient does not take any prescription or over the counter medications. The remainder of the patient’s history and physical exam is completely normal. The doctor refers the patient to a gastroenterologist for a stomach acid test and an upper gastrointestinal endoscopy which revealed that this patient is a heavy acid producer and has a gastric peptic ulcer. This ulcer is most likely found in which part of the stomach?
A. Multiple sites throughout the stomach
B. In the body
C. In the pyloric channel within 3 cm of the pylorus (Correct Answer)
D. Proximal gastroesophageal ulcer near the gastroesophageal junction
E. Along the lesser curve at the incisura angularis
Explanation: ***In the pyloric channel within 3 cm of the pylorus***
- Gastric ulcers in **heavy acid producers** characteristically occur in the **distal stomach**, particularly the **prepyloric region and pyloric channel**.
- This location represents the area of highest acid exposure in the stomach and shares pathophysiology similar to **duodenal ulcers**, which are the most common peptic ulcers in hypersecretory states.
- The pyloric channel location is exposed to both high acid and pepsin concentrations, making it vulnerable to ulceration in patients with increased acid production.
- **Type III gastric ulcers** (prepyloric) are specifically associated with acid hypersecretion, similar to duodenal ulcers.
*Along the lesser curve at the incisura angularis*
- While the **lesser curvature** is a common site for gastric ulcers, these are typically **Type II gastric ulcers** that occur in the body of the stomach.
- Lesser curvature ulcers are more commonly associated with **normal or low acid production** and impaired mucosal defense mechanisms rather than acid hypersecretion.
- The incisura angularis location is more typical of ulcers related to **H. pylori infection** or **NSAID use**, not primary acid overproduction.
*Proximal gastroesophageal ulcer near the gastroesophageal junction*
- Ulcers in this location represent **Type I gastric ulcers** or are related to **gastroesophageal reflux disease (GERD)**.
- These are not characteristic of heavy acid producers with typical gastric peptic ulcer disease.
- This location would suggest reflux esophagitis or Barrett's esophagus rather than a primary gastric ulcer.
*Multiple sites throughout the stomach*
- Multiple gastric ulcers suggest **NSAID use**, severe **stress ulcers** (Cushing's or Curling's), or widespread **H. pylori infection**.
- The clinical scenario describes a single ulcer in a patient not taking medications, making this unlikely.
- Heavy acid production typically causes a single, localized ulcer rather than multiple ulcers.
*In the body*
- Gastric body ulcers (**Type I**) are the most common type of gastric ulcer overall, but they occur in patients with **normal or decreased acid secretion**.
- These ulcers result from impaired mucosal defense rather than acid hypersecretion.
- A heavy acid producer would not typically develop an isolated body ulcer; this presentation is inconsistent with the pathophysiology described.
