Test yourself: Rheumatology


The following cases and commentary, which address rheumatology, are excerpted from ACP's Medical Knowledge Self-Assessment Program (MKSAP14).

Case 1: New-onset hypertension with anemia and thrombocytopenia

A 51-year-old man with a 4-year history of diffuse cutaneous systemic sclerosis is hospitalized for new-onset hypertension associated with anemia and thrombocytopenia. On admission, temperature was normal, pulse rate was 78/min, and blood pressure was 180/105 mm Hg. Neurologic examination was normal, and there was skin thickening over his face, chest, arms, hands, and legs. Lungs were clear to auscultation, and cardiac examination revealed a normal S1 and S2, an S4, and no S3. Abdominal examination was unremarkable. There was 1+ edema of both lower extremities.

Laboratory studies on admission were as follows: hemoglobin level, 9.8 g/dL (98 g/L); platelet count, 101,000 cells/µL (101 × 109 cells/L); blood urea nitrogen, 32 mg/dL (11.43 mmol/L); and creatinine, 1.4 mg/dL (123.79 µmol/L). Urinalysis showed 2+ protein with 3 to 5 erythrocytes/high-powered field and no casts. A peripheral blood smear showed 2+ erythrocyte fragments and schistocytes.

At the time of admission, therapy with captopril, 6.25 mg every 8 hours, was initiated. Within 24 hours, this dose was increased to 25 mg every 8 hours.

Three days after admission, blood pressure is 140/95 mm Hg. The creatinine level is now 2.1 mg/dL (185.68 µmol/L). Complete blood count is unchanged, and repeat urinalysis reveals 2+ protein with no erythrocytes or leukocytes.

Which of the following is the most appropriate management at this time?

A. Discontinue captopril; initiate calcium-channel blocker therapy
B. Continue to increase captopril dose
C. Perform plasmapheresis
D. Perform captopril renography

View correct answer for Case 1

Case 2: Hematemesis with acutely swollen right knee

A 58-year-old man hospitalized for hematemesis develops an acutely swollen right knee. His hematemesis is related to a bleeding ulcer associated with Helicobacter pylori infection. Over the past few years, he has had several acute attacks of peripheral monoarticular pain in his right knee. These attacks have been increasing in frequency and duration; during his last few episodes, he was unable to attend work. He does not drink alcoholic beverages and is otherwise well.

On laboratory studies, hemoglobin is 10 g/dL (100 g/L) and urate is 10.4 mg/dL (0.62 mmol/L). Arthrocentesis is performed, and synovial fluid analysis using polarized light microscopy reveals urate crystals.

His gout is successfully treated with intra-articular corticosteroids, and low-dose colchicine therapy is initiated to prevent further gouty attacks.

Which of the following is the most appropriate next step in this patient's management?

A. Low-protein and -purine diet
B. Allopurinol
C. 24-hour urine urate excretion; if findings are <1 g, initiate probenecid therapy
D. 24-hour urine urate excretion; if findings are >1 g, initiate allopurinol therapy

View correct answer for Case 2

Case 3: Systemic lupus erythematosus, severe left shoulder pain and low-grade fever

A 28-year-old woman with systemic lupus erythematosus is hospitalized for severe left shoulder pain and low-grade fever. The pain is constant, interferes with her sleep, and has a minimal pleuritic component. At age 18 years, she was diagnosed with lupus nephritis, which was treated with corticosteroids and cyclophosphamide. The last flare of her renal disease occurred 2 years ago, and she is now in remission. She has had two second-trimester miscarriages that occurred 1 and 3 years ago, respectively. Medications are hydroxychloroquine, 200 mg daily; low-dose aspirin; and prednisone, 5 mg every other day.

On physical examination, she is afebrile. There is facial scarring from discoid lupus erythematosus but no active lesions. On musculoskeletal examination, passive and active range of motion of the shoulders and neck are normal and do not elicit pain. Deep tendon reflexes, muscle strength, and neurologic examination of the upper extremities also are normal. The remainder of the examination is unremarkable.

Except for a platelet count of 114,000 cells/µL (114 × 109 cells/L), laboratory studies are unchanged from baseline values measured several months ago. Urinalysis reveals trace protein with no casts. Chest and shoulder radiographs are normal.

Which of the following is the most appropriate next step in this patient's management?

A. Increase prednisone dose to 40 mg/d
B. CT of the abdomen
C. MRI of the left shoulder
D. Aspirate the left shoulder joint

View correct answer for Case 3

Case 4: Cutaneous systemic sclerosis, abdominal pain and bloating

A 56-year-old man with a 10-year history of limited cutaneous systemic sclerosis comes to the emergency department for abdominal pain and bloating. He also has had five to seven episodes of large-volume, watery diarrhea for the past 5 days. Before the diarrhea developed, he was constipated for 1 week. He reports similar cyclical patterns of gastrointestinal symptoms for the past 3 months. He often fears leaving his home because of his urgent diarrhea and has had three episodes of fecal incontinence. He has been taking nifedipine for Raynaud's phenomenon and lansoprazole for gastroesophageal reflux disease for more than 5 years. The remainder of the history is unremarkable, and he has no surgical history. He has not recently taken antibiotics, traveled, or been exposed to anyone with a diarrheal illness.

On physical examination, he appears uncomfortable. Temperature is normal, pulse rate is 80/min, respiration rate is 22/min, and blood pressure is 120/60 mm Hg. He does not demonstrate orthostatic changes in blood pressure, but his pulse rate increases to 90/min when he rises. The lungs are clear to auscultation. Cardiovascular examination is normal. Abdominal examination reveals hyperactive bowel sounds, and the abdomen is mildly distended. There is diffuse tenderness but no guarding or rebound tenderness.

Complete blood count and metabolic panel are normal. An abdominal series reveals no free air under the diaphragm and a nonspecific bowel gas pattern.

Which of the following is the most appropriate next step in this patient's management?

A. 10-day course of oral vancomycin
B. 10-day course of oral ciprofloxacin
C. An increase in fluid intake; follow-up visit in 3 days
D. Loperamide after each loose bowel movement

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Case 5: Gout with right knee swelling and progressive pain

A 67-year-old man with a 10-year history of gout is evaluated in the emergency department for right knee swelling and progressive pain of 2 days' duration. He has not experienced an inciting trauma. Walking is now difficult because of the pain. He believes he may have had a fever. His gout typically involves his great toes, ankles, and/or knees. He also has diabetes, hyperlipidemia, and hypertension. He takes colchicine but recently discontinued this agent and has been taking ibuprofen with minimal relief. Additional medications are allopurinol, atorvastatin, glipizide, hydrochlorothiazide, enalapril, and aspirin.

On physical examination, temperature is 38.1°C (100.6°F), pulse rate is 95/min, respiration rate is 18/min, and blood pressure is 145/92 mm Hg. On musculoskeletal examination, the right knee is erythematous, warm, swollen, and very tender; any motion of this joint elicits pain. There are no other swollen joints, and the remainder of the examination is normal except for the presence of bilateral olecranon nodules.

On laboratory studies, hemoglobin is 13.7 g/dL (137 g/L), leukocyte count is 17,500/µL (17.5 × 109/L), and platelet count is 345,000/µL (345 × 109/L). Arthrocentesis is performed. The synovial fluid leukocyte count is 98,000/µL (98 × 109/L) (96% neutrophils). Polarized light microscopy reveals monosodium urate crystals, and Gram stain and culture of the synovial fluid have been ordered.

Which of the following is the most appropriate next step in this patient's management?

A. Discontinue allopurinol; add oral indomethacin, 50 mg three times daily
B. Discontinue allopurinol; add probenecid
C. Intravenous antibiotic therapy
D. Intra-articular methylprednisolone and lidocaine

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Case 6: Pregnancy with acute pain in left wrist and right knee

A 26-year-old woman in her first trimester of pregnancy is evaluated in the emergency department for an acutely painful left wrist and painful, swollen right knee. Four days ago, she developed flu-like symptoms characterized by migratory joint pains. She has particular difficulty holding a skillet and pouring coffee with either hand. Her pregnancy had been uncomplicated.

On physical examination, the right knee has a warm effusion and the left wrist is slightly warm but not swollen. Passive wrist motion is uncomfortable and resisted extension is extremely painful. The joint capsule of the knee is tender. There is a scant mucoid cervical discharge. The remainder of the examination is normal.

Blood, pharyngeal, cervical, rectal, and right knee cultures are obtained. Arthrocentesis of the knee yields 20 mL of fluid (leukocyte count, 14,000/µL [14 × 109/L]; 90% neutrophils). Gram stain is negative.

She is hospitalized, and intravenous ceftriaxone therapy is initiated. Two days later, she is only minimally improved. Cultures are negative.

Which of the following is the most appropriate next step in this patient's management?

A. Continue ceftriaxone
B. Discontinue ceftriaxone; perform serologic studies for parvovirus infections
C. Discontinue ceftriaxone; treat for reactive arthritis
D. Continue ceftriaxone; perform total hemolytic complement assay
E. Add vancomycin

View correct answer for Case 6

Case 7: Scrotal ulcer with headache and right eye pain

A 33-year-old man is evaluated in the emergency department for a 5-day history of headache and right eye pain. A week ago, he also developed an exquisitely painful scrotal ulcer. He does not have fever, neck stiffness, or joint pain. He has had intermittent oral ulcers for the past 5 years. He takes no medications and is monogamous.

On physical examination, temperature is 36.8°C (98.2°F), pulse rate is 85/min, respiration rate is 14/min, and blood pressure is 130/76 mm Hg. There are five ulcers on the oral mucosa. The right eye is inflamed with a ciliary flush, and a hypopyon is present. There is no nuchal rigidity. There is a 1-cm ulcer on his scrotum.

On laboratory studies, hemoglobin is 11.1 g/dL (111 g/L) and leukocyte count is 15,600/µL (15.6 × 109/L). CT scan of the head is normal. Lumbar puncture is performed, and cerebrospinal fluid studies reveal a leukocyte count of 13/µL (13 × 106/L)(100% lymphocytes); Gram stain is negative.

Which of the following is the most likely diagnosis?

A. Syphilis
B. Chancroid
C. Behçet's disease
D. Systemic lupus erythematosus
E. Herpes simplex virus infection

View correct answer for Case 7


Answers and commentary

Case 1

Correct answer: B. Continue to increase captopril dose.

The most appropriate management for this patient is further increasing his captopril dose. This patient was hospitalized with scleroderma renal crisis. Angiotensin-converting enzyme (ACE) inhibitors are believed to be the most effective agents for preserving or improving renal function in scleroderma renal crisis. Therefore, continuation of these agents is indicated even if the creatinine level continues to increase and the patient requires hemodialysis, because improvements in renal function with this therapy have been reported even after 18 months of dialysis. One-year survival of scleroderma patients with renal crisis has been shown to increase from 15% to 76% with aggressive treatment using ACE inhibitors.

Discontinuation of captopril is contraindicated in this patient. Although his creatinine levels have increased, his underlying renal crisis is responsible, not the ACE inhibitor. In addition, his blood pressure has not been fully controlled. Plasmapheresis does not help to manage scleroderma renal crisis. Moreover, this therapy is contraindicated in patients taking ACE inhibitors. Flushing, hypotension, and gastrointestinal symptoms have been shown to develop during plasmapheresis in patients receiving ACE inhibitors, possibly due to increased kinin generation.

Captopril renography is not indicated because this patient does not have increased risk for bilateral renal artery stenosis. His increasing creatinine level is not unexpected and should not raise clinical suspicion for an underlying process in addition to scleroderma renal crisis.

Key points

  • Angiotensin-converting enzyme inhibitors are the most effective agents for preserving or improving renal function in scleroderma renal crisis.
  • Continuation of angiotensin-converting enzyme inhibitor therapy is indicated in scleroderma renal crisis even if the creatinine level continues to increase and the patient requires dialysis.

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Case 2

Correct answer: B. Allopurinol.

Allopurinol therapy is indicated for this patient because of the severity of his condition. A target urate level of approximately 6 mg/dL should be achieved in this patient, which would allow resorption of urate deposits from the tissues. Allopurinol, 50 mg/d to 100 mg/d, is initially indicated, but this dose should be increased, guided by regular measurements of urate levels, as needed to achieve the target urate level. Measurement of urate levels is indicated approximately 3 to 4 weeks after each change in a patient's allopurinol dose. Allopurinol therapy to more than 300 mg/d is necessary for approximately 50% of patients with hyperuricemia to achieve the target urate level of less than 6 mg/dL.

Patients who initiate therapy with a hypouricemic agent have an increased risk for developing more frequent attacks of gout during the first few months of treatment. Prophylactic anti-inflammatory therapy (usually colchicine, 0.6 mg once or twice daily) is therefore indicated for these patients, although this therapy should be administered only as tolerated because of the risk for diarrhea. A lower dose of colchicine is indicated for patients with mild renal insufficiency.

Dietary change alone most likely will not adequately decrease urate levels, although avoidance or limited use of alcoholic beverages, such as mineral spirits and beer, is beneficial in this setting. Uricosuric agents available in the United States are generally less effective compared with allopurinol in decreasing a patient's urate level and require patients to consume extra fluids. These agents also are not indicated for patient who excrete more than 1 g of urate/24 h, because of the risk for inducing nephrolithiasis. Allopurinol is equally effective in the setting of inefficient excretion or overproduction of urate. Therefore, therapy with this agent may be initiated regardless of the results of this study.

Key points

  • Allopurinol is equally effective in the setting of inefficient excretion and overproduction of urate.
  • Allopurinol at a dose of more than 300 mg/d is necessary for approximately 50% of patients with hyperuricemia in order to achieve urate levels of less than 6 mg/dL.

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Case 3

Correct answer: B. CT of the abdomen.

CT of the abdomen is indicated before this patient is discharged from the hospital. Severe pain around the shoulder in patients with no abnormal examination findings suggests that pain may be referred. Left shoulder pain may be referred from the neck; chest; or subdiaphragmatic areas, including the spleen. Because examination and radiographs of the neck, shoulder, and chest are normal, these areas are not likely origins of this patient's referred pain. Therefore, further evaluation of the spleen or subdiaphragmatic area is indicated, particularly in the setting of pain with a pleuritic component.

This patient's history of miscarriages and decreased platelet count particularly raise clinical suspicion for the antiphospholipid antibody syndrome, and splenic infarction associated with this condition may be causing her pain. Splenic infarction often does not cause fever, abdominal pain, or abnormal findings on abdominal examination, but an associated friction rub over the infarcted area may be audible.

An increase in prednisone to moderate or high doses as therapy for a disease flare is indicated for patients with systemic lupus erythematosus only after other possibilities are excluded. Avascular necrosis may cause severe joint pain, and corticosteroid-induced avascular necrosis frequently develops in the shoulder. MRI may be indicated to definitively establish a diagnosis of avascular necrosis. However, this diagnosis is less likely in this patient because pain associated with avascular necrosis usually can be elicited on musculoskeletal examination and would not have a pleuritic component. Aspiration of the shoulder joint is indicated only if examination findings suggest shoulder synovitis.

Key point

  • Left shoulder pain may be referred from the neck; chest; or subdiaphragmatic area, including the spleen.

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Case 4

Correct answer: B. 10-day course of oral ciprofloxacin.

Ciprofloxacin therapy is the most appropriate next step in this patient's management. This patient has limited cutaneous systemic sclerosis with gastrointestinal involvement. His symptoms are consistent with small-bowel bacterial overgrowth caused by gastrointestinal dysmotility. These symptoms typically respond to broad-spectrum oral antibiotic therapy to alter the bacterial growth pattern. Antibiotic coverage for bowel flora, such as gram-negative rods and anaerobic bacteria, is indicated.

Vancomycin therapy is effective in patients with Clostridium difficile infection. However, this patient has no specific risk factors for this condition. In addition, the gram-positive coverage associated with vancomycin is not sufficient to treat a bacterial overgrowth pattern. Oral fluid replacement therapy alone will not cause clinical improvement in this setting. Opioid antidiarrheal therapy is not indicated for patients with scleroderma because it may worsen intestinal motility disorders.

Key points

  • Small-bowel bacterial overgrowth is a common cause of diarrhea in patients with scleroderma and is treated with intermittent broad-spectrum antibiotics.
  • Opioid antidiarrheal therapy is not indicated for patients with scleroderma because it may worsen intestinal motility disorders.

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Case 5

Correct answer: C. Intravenous antibiotic therapy.

This patient should be hospitalized for intravenous antibiotic therapy until Gram stain and culture of the synovial fluid are proved negative. This patient's significantly elevated synovial fluid leukocyte count, peripheral blood leukocytosis, and fever are highly suggestive of infection. In patients with gout, a synovial fluid leukocyte count of >50,000/µL (> 50 × 109/L) should raise clinical suspicion for a complicating condition, such as joint infection. Patients with joint abnormalities such as gout also have an increased risk for joint infection. In addition, risk for infection also is increased in patients with diabetes. Therefore, although this patient has gout, an infectious cause for his symptoms should be considered.

The addition of indomethacin is appropriate to manage a gout flare, if there are no contraindications to its use. However, discontinuation of allopurinol is not indicated in the setting of acute gout. Initiation of probenecid, or any change in hypouricemic therapy, during a gout flare is not indicated because the associated change in urate levels may worsen or prolong the flare. Intra-articular corticosteroid therapy is contraindicated until a diagnosis of infection is definitively excluded.

Key points

  • Patients with joint abnormalities have an increased risk for joint infection.
  • Intra-articular corticosteroid therapy is contraindicated until infection is excluded.

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Case 6

Correct answer: A. Continue ceftriaxone.

Ceftriaxone therapy should be continued in this patient. Sexually active patients who develop migratory arthralgias and subsequent oligoarthritis and present with wrist tenosynovitis have strong clinical suspicion for disseminated gonococcal infection. Skin lesions may not be present, and cultures may be negative in this setting, particularly if antibiotic therapy is administered before cultures are performed. Antibiotic response in this setting may not be rapid, and 48 hours is not sufficient time for a complete response to therapy. Therefore, no additional therapy is indicated at this time. Screening for chlamydia, HIV, and other sexually transmitted diseases should be performed once gonorrhea infection is established.

Parvovirus infection in adults is characterized by arthritis and often is not associated with the characteristic rash that develops in affected children. Nevertheless, continuation of antibiotic therapy for a few more days is indicated before testing for parvovirus infection to ensure that this patient is unresponsive to therapy for disseminated gonorrhea. In patients with negative culture findings, a complete response to appropriate antibiotic therapy often is the gold standard for establishing a diagnosis of disseminated gonorrhea. Gonorrhea infection must be excluded by negative culture results and a lack of response to antibiotic therapy before a diagnosis of reactive arthritis is established.

Terminal complement component deficiency is characterized by recurrent episodes of disseminated neisserial infection but is rare. Therefore, evaluation for this condition is not indicated on initial presentation of a patient with suspected gonorrhea. In addition, terminal complement component deficiency does not alter a patient's response to adequate antibiotic therapy.

Key point

  • A complete response to appropriate antibiotic therapy for disseminated gonorrhea may take up to 72 hours.

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Case 7

Correct answer: C. Behçet's disease.

This patient most likely has Behçet's disease, a multisystem inflammatory disease characterized by recurrent aphthous oral ulcers and at least two or more of the following features: recurrent genital ulceration, eye or cutaneous lesions, or positive findings on pathergy testing (development of an erythematous papule >5 mm in diameter or a pustular lesion 24 to 48 hours after skin prick by needle). Features associated with Behçet's disease that have the greatest potential for morbidity or mortality include central nervous system disease, such as aseptic meningitis and parenchymal lesions; ocular disease that may cause blindness; vascular thrombosis; arterial aneurysms; and gastrointestinal disease, which is characterized by nausea, abdominal pain, or diarrhea.

Gastrointestinal ulcerations may occur in the terminal ileum, cecum, and ascending colon. This patient's headache and cerebrospinal fluid findings are consistent with aseptic meningitis. He also has anterior uveitis and hypopyon (purulent material in the anterior chamber of the eye), which is characteristic of Behçet's disease.

Clinical suspicion for primary syphilis should be raised in the setting of painless genital ulcers, but this condition would not cause ocular inflammation, oral ulcers, or aseptic meningitis. Although chancroid causes ragged, purulent, painful ulcers, and one third of affected patients have a painful ulcer and concomitant tender lymphadenopathy, chancroid does not cause uveitis, oral ulcers, or aseptic meningitis. Patients with systemic lupus erythematosus typically have malar rash, serositis, renal disease, or cytopenias, which this patient does not have. In addition, systemic lupus erythematosus also does not cause genital ulceration. Systemic symptoms, including fever, headache, and malaise, occur during initial episodes of genital herpes simplex virus infection in 40% of affected men and 70% of affected women. However, genital herpes is associated with inguinal lymphadenopathy and does not cause ocular inflammation.

Key point

  • Behçet's disease is characterized by recurrent aphthous oral ulcers and at least two or more of the following features: recurrent genital ulceration, eye or cutaneous lesions, or positive findings on pathergy testing.