APRIL 2012 Rheumatology Quiz

1. A 26-year-old woman is evaluated for a 2-month history of pain and swelling in the hands and daily morning stiffness that lasts for 3 to 4 hours. She is 4 months postpartum, and her pregnancy was without complications. She has no history of rash and is otherwise well. Her only medication is ibuprofen, which has not sufficiently relieved her symptoms. On physical examination, temperature is normal, blood pressure is 110/68 mm Hg, pulse rate is 82/min, and respiration rate is 16/min. The second and third proximal interphalangeal and metacarpophalangeal joints and the wrists are tender and swollen bilaterally. Laboratory studies show an erythrocyte sedimentation rate of 67 mm/h, and titers of IgM antibodies against parvovirus B19 are negative. Which of the following is the most likely diagnosis?

Gout

Osteoarthritis

Parvovirus B19 infection

Rheumatoid arthritis

The patient's presentation of pain and swelling in the hands, morning stiffness, and symmetrical joint involvement suggests an inflammatory arthritis, rather than a degenerative condition such as osteoarthritis. The negative IgM antibodies against parvovirus B19 also make an infection less likely. The elevated erythrocyte sedimentation rate (ESR) further supports an inflammatory process. Therefore, the most likely diagnosis is rheumatoid arthritis.

Explanation

The patient's presentation of pain and swelling in the hands, morning stiffness, and symmetrical joint involvement suggests an inflammatory arthritis, rather than a degenerative condition such as osteoarthritis. The negative IgM antibodies against parvovirus B19 also make an infection less likely. The elevated erythrocyte sedimentation rate (ESR) further supports an inflammatory process. Therefore, the most likely diagnosis is rheumatoid arthritis.

2. A 28-year-old woman is evaluated for a 3-week history of pain and swelling of the right knee and ankle. For the past 6 weeks, she has had diffuse, crampy abdominal pain. For the past week, the pain has been accompanied by four to six daily episodes of bloody diarrhea and fecal urgency. She has lost approximately 1.5 kg (3.3 lb) since the onset of her symptoms. She has not noticed a rash or other joint or soft-tissue involvement. She has not traveled outside of her hometown and has a monogamous sexual relationship with her husband. She has no other medical problems and does not take any medications. On physical examination, temperature is 37.7 °C (99.9 °F), blood pressure is 128/72 mm Hg, pulse rate is 98/min, and respiration rate is 18/min. The abdomen is soft and diffusely tender to palpation. Bowel sounds are normal, and there is no organomegaly. Rectal examination reveals tenderness of the rectal canal and stool associated with bright red blood. The right ankle and knee are swollen and slightly warm to the touch, and range of motion of these joints elicits pain. The remainder of the physical examination is normal. Plain radiographs of the ankle and knee are normal. Arthrocentesis is performed. Synovial fluid analysis reveals a leukocyte count of 14,000/µL (92% polymorphonuclear cells, 8% macrophages). Which of the following is the most likely cause of this patient's joint symptoms?

Crystal-induced arthritis

Enteropathic arthritis

Gonococcal arthritis

Whipple disease

The patient's symptoms of abdominal pain, bloody diarrhea, and weight loss, along with joint symptoms involving the knee and ankle, suggest an underlying inflammatory bowel disease (IBD). Enteropathic arthritis is a type of peripheral arthritis that occurs in association with IBD, typically affecting large joints such as the knee and ankle. The synovial fluid analysis showing a leukocyte count with a predominance of polymorphonuclear cells further supports the diagnosis of enteropathic arthritis. Crystal-induced arthritis, gonococcal arthritis, and Whipple disease are less likely to present with the combination of gastrointestinal and joint symptoms seen in this patient.

Explanation

The patient's symptoms of abdominal pain, bloody diarrhea, and weight loss, along with joint symptoms involving the knee and ankle, suggest an underlying inflammatory bowel disease (IBD). Enteropathic arthritis is a type of peripheral arthritis that occurs in association with IBD, typically affecting large joints such as the knee and ankle. The synovial fluid analysis showing a leukocyte count with a predominance of polymorphonuclear cells further supports the diagnosis of enteropathic arthritis. Crystal-induced arthritis, gonococcal arthritis, and Whipple disease are less likely to present with the combination of gastrointestinal and joint symptoms seen in this patient.

3. A 24-year-old woman is evaluated for a 2-week history of persistent pain and swelling in the right foot and knee and the left heel. One month ago, she developed an episode of conjunctivitis that resolved spontaneously. She also had an episode of severe diarrhea 2 months ago while traveling to Central America that was successfully treated with a 3-day course of ciprofloxacin and loperamide. She has not had other infections of the gastrointestinal or genitourinary tract, rash, or oral ulcerations. Her weight has been stable, and she has not had abdominal pain, blood in the stool, or changes in her bowel habits. She has had only one sexual partner 6 years ago. She otherwise feels well, has no other medical problems, and takes no medications other than acetaminophen for joint pain. On physical examination, vital signs, including temperature, are normal. Cutaneous examination, including the nails and oral mucosa, is normal. There is no evidence of conjunctivitis or iritis. Musculoskeletal examination reveals swelling, warmth, and tenderness of the right knee and ankle. There is tenderness to palpation at the insertion site of the left Achilles tendon. Which of the following is the most likely diagnosis?

Enteropathic arthritis

Psoriatic arthritis

Reactive arthritis

Rheumatoid arthritis

The patient's symptoms of pain and swelling in multiple joints, as well as a history of recent conjunctivitis and diarrhea, are consistent with reactive arthritis. Reactive arthritis is an inflammatory arthritis that occurs following an infection, typically involving the gastrointestinal or genitourinary tract. It is characterized by joint inflammation, often affecting the lower extremities, and can be triggered by certain infections such as Chlamydia, Salmonella, or Campylobacter. The absence of other symptoms such as rash or oral ulcerations, as well as the patient's stable weight and lack of abdominal pain or changes in bowel habits, make other diagnoses less likely.

Explanation

The patient's symptoms of pain and swelling in multiple joints, as well as a history of recent conjunctivitis and diarrhea, are consistent with reactive arthritis. Reactive arthritis is an inflammatory arthritis that occurs following an infection, typically involving the gastrointestinal or genitourinary tract. It is characterized by joint inflammation, often affecting the lower extremities, and can be triggered by certain infections such as Chlamydia, Salmonella, or Campylobacter. The absence of other symptoms such as rash or oral ulcerations, as well as the patient's stable weight and lack of abdominal pain or changes in bowel habits, make other diagnoses less likely.

4. A 67-year-old man is evaluated in the emergency department for a 2-week history of pain involving the left hip. He has had no fever. Four years ago, he underwent total arthroplasty of the left hip joint to treat osteoarthritis. One month ago, he underwent tooth extraction for an abscessed tooth. On physical examination, temperature is 36.6 °C (98.0 °F), blood pressure is normal, and pulse rate is 90/min. Cardiopulmonary examination is normal. A well-healed surgical scar is present over the left hip, and there is no warmth or tenderness. External rotation of the left hip joint is markedly painful. Laboratory studies reveal an erythrocyte sedimentation rate of 88 mm/h. Radiograph of the left hip shows a normally seated left hip prosthesis. Fluoroscopic-guided arthrocentesis is performed. The synovial fluid leukocyte count is 38,000/µL (90% neutrophils). Polarized light microscopy of the fluid shows no crystals, and Gram stain is negative. Culture results are pending. Which of the following is the most likely diagnosis?

Aseptic loosening

Gout

Pigmented villonodular synovitis

Prosthetic joint infection

The patient's history of pain in the left hip after total arthroplasty, along with the presence of a well-healed surgical scar, suggests a potential complication related to the hip prosthesis. The markedly painful external rotation of the left hip joint, along with the elevated erythrocyte sedimentation rate and synovial fluid leukocyte count, indicates an inflammatory process. The absence of crystals on polarized light microscopy and negative Gram stain make gout and crystal-induced arthritis less likely. Pigmented villonodular synovitis is also unlikely as it typically presents with joint effusion and hemosiderin-laden macrophages in the synovial fluid. Therefore, the most likely diagnosis is a prosthetic joint infection.

Explanation

The patient's history of pain in the left hip after total arthroplasty, along with the presence of a well-healed surgical scar, suggests a potential complication related to the hip prosthesis. The markedly painful external rotation of the left hip joint, along with the elevated erythrocyte sedimentation rate and synovial fluid leukocyte count, indicates an inflammatory process. The absence of crystals on polarized light microscopy and negative Gram stain make gout and crystal-induced arthritis less likely. Pigmented villonodular synovitis is also unlikely as it typically presents with joint effusion and hemosiderin-laden macrophages in the synovial fluid. Therefore, the most likely diagnosis is a prosthetic joint infection.

5. A 32-year-old African-American woman presents to her primary care doctor complaining of fatigue, joint stiffness and pain, mouth ulcers, and hair loss. She first noticed fatigue about 6 months ago, and at that time, a complete blood count and thyroid function tests were normal. Since then, she feels like her symptoms are getting progressively worse. She now states that she sleeps 10 h but continues to feel fatigued. She has also developed joint stiffness and pain in her hands, wrists, and knees that is present for about 1 h upon awakening. For the past 1 month, she has had an area of hair loss on her scalp associated with a raised scaly rash. During this time, she intermittently developed painful mouth ulcerations that would spontaneously resolve. She also reports a severe "sunburn" on her face, upper neck, and back that occurred after <1 h of sun exposure and which was unusual for her. Her past medical history is positive for two spontaneous vaginal deliveries that were uncomplicated. She has not had any prior miscarriages. She is taking oral contraceptive pills and has no allergies. On physical examination, the vital signs are: temperature 36.6°C, blood pressure 136/82 mmHg, heart rate 88 beats/min, respiratory rate 12 breaths/min, SaO2 98% on room air. She has a circular raised area on her right parietal area that is 3 cm in diameter. This area has an atrophic center with hair loss and is erythematous with a hyperpigmented rim. Her conjunctiva are pink and no scleral icterus is present. The oropharynx shows a single 2-mm aphthous ulceration on the buccal mucosa. Both wrists show some slight tenderness with palpation and pain with range of motion. The patient is incapable of closing her hands tightly. In addition, there is warmth and a possible effusion in the right knee and tenderness with range of motion in the left knee. Cardiovascular, pulmonary, abdominal, and neurologic examinations are normal. Laboratory studies show the following: White blood cell count 2300/ L Hemoglobin 8.9 g/dL Hematocrit 26.7% Mean corpuscular volume 88 fL Mean corpuscular hemoglobin count 32 g/dL Platelet 98,000/ L The differential is 80% polymorphonuclear cells, 12% lymphocytes, 7% monocytes, 1% eosinophils, and 1% basophils. An antinuclear antibody (ANA) is positive at a titer of 1:640. Antibodies to double-stranded DNA are negative, and anti-Smith antibodies are positive at a titer of 1:160. The rheumatoid factor level is 37 IU/L. What is the most likely diagnosis?

Behcet's disease

Discoid lupus erythematosus

Rheumatoid arthritis

Sarcoidosis

Systemic lupus erythematosus

The patient's symptoms and laboratory findings are consistent with systemic lupus erythematosus (SLE). SLE is a chronic autoimmune disease that can affect multiple organ systems. The patient's symptoms of fatigue, joint stiffness and pain, mouth ulcers, and hair loss are characteristic of SLE. The positive ANA and anti-Smith antibodies further support the diagnosis. The low white blood cell count, anemia, and thrombocytopenia seen in the laboratory findings are common hematologic manifestations of SLE. The presence of a malar rash and photosensitivity also suggest SLE. Therefore, SLE is the most likely diagnosis in this case.

Explanation

The patient's symptoms and laboratory findings are consistent with systemic lupus erythematosus (SLE). SLE is a chronic autoimmune disease that can affect multiple organ systems. The patient's symptoms of fatigue, joint stiffness and pain, mouth ulcers, and hair loss are characteristic of SLE. The positive ANA and anti-Smith antibodies further support the diagnosis. The low white blood cell count, anemia, and thrombocytopenia seen in the laboratory findings are common hematologic manifestations of SLE. The presence of a malar rash and photosensitivity also suggest SLE. Therefore, SLE is the most likely diagnosis in this case.

6. A 41-year-old woman is evaluated for intermittent pain and cyanosis of the fingers that is usually associated with exposure to cold temperatures or stress. She does not smoke, and her efforts to keep room temperatures warm and to wear gloves and layers of clothing to maintain her core temperature have not been successful in managing her symptoms. She was diagnosed with limited cutaneous systemic sclerosis 1 year ago. She also has gastroesophageal reflux disease. Her only medication is omeprazole. On physical examination, temperature is 37.0 °C (98.6 °F), blood pressure is 128/72 mm Hg, and pulse rate is 88/min. Cutaneous examination of the hands shows sclerodactyly. Radial and ulnar pulses are 2+ and equal bilaterally. Which of the following is the most appropriate additional treatment for this patient?

Amlodipine

Isosorbide dinitrate

Prednisone

Propranolol

Amlodipine is the most appropriate additional treatment for this patient because she has symptoms consistent with Raynaud phenomenon, which is commonly seen in patients with limited cutaneous systemic sclerosis. Amlodipine, a calcium channel blocker, can help to improve blood flow and reduce vasospasm, which will alleviate the pain and cyanosis of her fingers. Isosorbide dinitrate, a vasodilator, may also be effective in treating Raynaud phenomenon, but amlodipine is generally preferred as the initial treatment. Prednisone and propranolol are not indicated for the management of Raynaud phenomenon.

Explanation

Amlodipine is the most appropriate additional treatment for this patient because she has symptoms consistent with Raynaud phenomenon, which is commonly seen in patients with limited cutaneous systemic sclerosis. Amlodipine, a calcium channel blocker, can help to improve blood flow and reduce vasospasm, which will alleviate the pain and cyanosis of her fingers. Isosorbide dinitrate, a vasodilator, may also be effective in treating Raynaud phenomenon, but amlodipine is generally preferred as the initial treatment. Prednisone and propranolol are not indicated for the management of Raynaud phenomenon.

7. A 22-year-old woman is evaluated for pain and swelling of the left knee of 3 months' duration. She has pain with weight bearing, at rest, and during the night but no morning stiffness, warmth, or erythema. Four years ago, she was diagnosed with systemic lupus erythematosus. She also has a 2-year history of glomerulonephritis. She recently completed an extended course of mycophenolate mofetil and a tapering course of high-dose prednisone. Current medications are low-dose prednisone and hydroxychloroquine. On physical examination, temperature is normal, blood pressure is 128/72 mm Hg, pulse rate is 88/min, and respiration rate is 20/min. There is a large effusion on the left knee but no warmth or erythema. Range of motion of the left knee elicits pain. Synovial fluid leukocyte count is 800/µL (78% lymphocytes, 22% macrophages). Plain radiograph of the left knee shows no bony abnormalities. Which of the following is the most likely diagnosis?

Avascular necrosis

Bacterial septic arthritis

Crystal-induced arthritis

Fungal arthritis

The most likely diagnosis in this case is avascular necrosis. Avascular necrosis is a condition where the blood supply to a bone is disrupted, leading to bone cell death. The patient's symptoms of pain and swelling in the left knee, along with the large effusion and pain with range of motion, are consistent with avascular necrosis. Additionally, the absence of warmth or erythema suggests that there is no active infection, making bacterial septic arthritis less likely. Crystal-induced arthritis and fungal arthritis would typically present with different clinical features and would not be the most likely diagnosis in this case.

Explanation

The most likely diagnosis in this case is avascular necrosis. Avascular necrosis is a condition where the blood supply to a bone is disrupted, leading to bone cell death. The patient's symptoms of pain and swelling in the left knee, along with the large effusion and pain with range of motion, are consistent with avascular necrosis. Additionally, the absence of warmth or erythema suggests that there is no active infection, making bacterial septic arthritis less likely. Crystal-induced arthritis and fungal arthritis would typically present with different clinical features and would not be the most likely diagnosis in this case.

8. A 42-year-old Turkish man presents to his physician complaining of recurring ulcers in the mouth and on his penis. He states that the ulcers are painful and last for about 2 weeks before spontaneously resolving. In addition, he intermittently gets skin lesions that he describes as painful nodules on his lower extremities. You suspect that he has Behçet's syndrome. A pathergy test is performed. What response would you expect after injecting 0.3 mL of sterile saline under the skin?

Development of 10 mm of induration with overlying erythema after 72 h

Development of a 2- to 3-mm papule at the site of insertion in 2–3 days

Development of granulomatous inflammation 4–6 weeks after the injection

Development of an urticarial reaction within 15 min

No reaction

A pathergy test is used to diagnose Behçet's syndrome, which is characterized by abnormal immune system activity. In this test, a small amount of saline is injected under the skin. A positive result is indicated by the development of a small papule (a raised bump) at the site of insertion within 2-3 days. This response is due to the hyperreactivity of the immune system in individuals with Behçet's syndrome. The other options, such as induration with erythema after 72 hours or granulomatous inflammation after 4-6 weeks, are not characteristic of a positive pathergy test in Behçet's syndrome.

Explanation

A pathergy test is used to diagnose Behçet's syndrome, which is characterized by abnormal immune system activity. In this test, a small amount of saline is injected under the skin. A positive result is indicated by the development of a small papule (a raised bump) at the site of insertion within 2-3 days. This response is due to the hyperreactivity of the immune system in individuals with Behçet's syndrome. The other options, such as induration with erythema after 72 hours or granulomatous inflammation after 4-6 weeks, are not characteristic of a positive pathergy test in Behçet's syndrome.

9. A 48-year-old woman is evaluated for a 4-month history of pain in the shoulders, neck, and lower back. She also has fatigue and difficulty sleeping. She does not have rash, chest pain, joint pain, anorexia, weight loss, fever, or depressed mood. On physical examination, vital signs are normal. Thyroid examination is normal. Musculoskeletal examination reveals widespread soft-tissue pain. The joints are not swollen. Muscle strength testing is limited because of pain. Deep-tendon reflexes and sensation are intact. Laboratory studies: Complete blood count Normal Erythrocyte sedimentation rate 18 mm/h Serum creatine kinase 164 U/L Serum thyroid-stimulating hormone 3.0 µU/mL (3.0 mU/L) Which of the following is the most appropriate next step in this patient's management?

Aerobic exercise program

Antinuclear antibody assay

Electromyography

Ibuprofen

Prednisone

This patient's presentation is consistent with fibromyalgia, a chronic condition characterized by widespread musculoskeletal pain and fatigue. The absence of joint swelling and normal laboratory findings make other causes less likely. The most appropriate next step in management is to initiate an aerobic exercise program. Exercise has been shown to improve symptoms and overall function in patients with fibromyalgia. Antinuclear antibody assay and electromyography are not indicated based on the clinical presentation. Ibuprofen may provide some symptomatic relief but does not address the underlying condition. Prednisone is not recommended as first-line therapy for fibromyalgia.

Explanation

This patient's presentation is consistent with fibromyalgia, a chronic condition characterized by widespread musculoskeletal pain and fatigue. The absence of joint swelling and normal laboratory findings make other causes less likely. The most appropriate next step in management is to initiate an aerobic exercise program. Exercise has been shown to improve symptoms and overall function in patients with fibromyalgia. Antinuclear antibody assay and electromyography are not indicated based on the clinical presentation. Ibuprofen may provide some symptomatic relief but does not address the underlying condition. Prednisone is not recommended as first-line therapy for fibromyalgia.

10. A 27-year-old female with SLE is in remission; current treatment consists of azathioprine 75 mg/d and prednisone 5 mg/d. Last year she had a life-threatening exacerbation of her disease. She now strongly desires to become pregnant. Which of the following is the least appropriate action to take?

Advise her that the risk of spontaneous abortion is high

Warn her that exacerbations can occur in the first trimester and in the postpartum period

Tell her it is unlikely that a newborn will have lupus

Advise her that fetal loss rates are higher if anticardioplipin antibiodies are detected in her serum

Stop the prednisone just before she attempts to become pregnant

The least appropriate action to take in this situation is to stop the prednisone just before she attempts to become pregnant. Prednisone is a corticosteroid that is commonly used to manage autoimmune diseases like SLE. Stopping prednisone abruptly can lead to a flare-up of the disease, which can be harmful to both the mother and the fetus. It is important to maintain disease control during pregnancy to minimize the risk of complications. Therefore, it is not advisable to stop the prednisone just before attempting to become pregnant.

Explanation

The least appropriate action to take in this situation is to stop the prednisone just before she attempts to become pregnant. Prednisone is a corticosteroid that is commonly used to manage autoimmune diseases like SLE. Stopping prednisone abruptly can lead to a flare-up of the disease, which can be harmful to both the mother and the fetus. It is important to maintain disease control during pregnancy to minimize the risk of complications. Therefore, it is not advisable to stop the prednisone just before attempting to become pregnant.

11. Which of the following joints are typically spared in osteoarthritis (OA)?

Ankle

Cervical spine

Distal interphalangeal joint

Hip

Knee

The ankle joint is typically spared in osteoarthritis (OA) because it is not a weight-bearing joint and is less susceptible to the degenerative changes that occur in OA. Weight-bearing joints such as the hip and knee are more commonly affected by OA due to the constant stress and strain they endure. The cervical spine and distal interphalangeal joint are also commonly affected by OA, but the ankle joint is typically spared from these degenerative changes.

Explanation

The ankle joint is typically spared in osteoarthritis (OA) because it is not a weight-bearing joint and is less susceptible to the degenerative changes that occur in OA. Weight-bearing joints such as the hip and knee are more commonly affected by OA due to the constant stress and strain they endure. The cervical spine and distal interphalangeal joint are also commonly affected by OA, but the ankle joint is typically spared from these degenerative changes.

12. A 53-year-old man is evaluated in the emergency department for a 2-day history of acute swelling and pain in the right knee. He also has had fever up to 38.3 °C (101.0 °F). Three weeks ago, he was evaluated in the emergency department for cellulitis. Medical history is significant for chronic tophaceous gout and hypertension. Medications are allopurinol, atenolol, and enalapril. He has a monogamous sexual relationship with his wife of 30 years. On physical examination, temperature is 38.1 °C (100.5 °F), blood pressure is 124/50 mm Hg, and pulse rate is 88/min. Cardiopulmonary examination is normal. Tophi are present on both elbows. The right fourth proximal interphalangeal joint and left third metacarpophalangeal joint have soft-tissue swelling but no warmth or erythema. The right knee is markedly swollen and has overlying warmth and erythema. Palpation of this joint elicits pain. Laboratory studies reveal a leukocyte count of 15,000/µL (15 m 109/L). Arthrocentesis is performed. The synovial fluid leukocyte count is 110,000/µL (95% neutrophils). Polarized light microscopy of the fluid reveals negatively birefringent monosodium urate crystals. Gram stain of the aspirated fluid is negative. Culture results are pending. Which of the following is the most appropriate treatment for this patient?

Ciprofloxacin

Intra-articular corticosteroids

Prednisone

Vancomycin

The patient's history, physical examination findings, and laboratory results are consistent with acute gouty arthritis. The presence of tophi, chronic tophaceous gout, and monosodium urate crystals in the synovial fluid confirm the diagnosis. The patient also has signs of infection with fever, leukocytosis, and warmth and erythema over the affected joint. Therefore, the most appropriate treatment for this patient is Vancomycin, as it covers for potential bacterial infection in the joint.

Explanation

The patient's history, physical examination findings, and laboratory results are consistent with acute gouty arthritis. The presence of tophi, chronic tophaceous gout, and monosodium urate crystals in the synovial fluid confirm the diagnosis. The patient also has signs of infection with fever, leukocytosis, and warmth and erythema over the affected joint. Therefore, the most appropriate treatment for this patient is Vancomycin, as it covers for potential bacterial infection in the joint.

13. A 63-year-old white female is admitted to the hospital complaining of hemoptysis and shortness of breath. She had been well until 3 months ago, when she noted vague symptoms of fatigue and a 10-lb unintentional weight loss. Past medical history is notable only for osteoporosis. Her current symptoms began on the day of presentation with the expectoration of >200 mL of red blood in the emergency department. On physical examination, the patient is in marked respiratory distress with a respiratory rate of 44 breaths per minute. Oxygen saturation is 78% on room air and 88% on nonrebreather mask. Pulse is 120 beats/min, with a blood pressure of 170/110. There are diffuse crackles throughout both lung fields, and the cardiac examination is significant only for a regular tachycardia. There are no rashes or joint swellings. Laboratory studies reveal a hemoglobin of 10.2 mg/dL with a mean corpuscular volume (MCV) of 88 m3 (fL). The white blood cell count is 9760/mm3. Blood urea nitrogen (BUN) is 78 mg/dL, and creatinine is 3.2 mg/dL. The urinalysis shows 1+ proteinuria, moderate hemoglobin, 25 to 35 red blood cells (RBC) per high-power field, and occasional RBC casts. Chest computed tomography (CT) shows diffuse alveolar infiltrates consistent with alveolar hemorrhage. The antimyeloperoxidase titer is positive at 126 U/mL (normal <1.4 U/mL). What is the most likely diagnosis?

Goodpasture's disease

Granulomatosis with Polyangitis (formerly Wegener’s granulomatosis)

Microscopic polyangiitis

Polyarteritis nodosa

Cryoglobulinemia

The most likely diagnosis in this case is microscopic polyangiitis. This is supported by the patient's symptoms of hemoptysis, shortness of breath, fatigue, and unintentional weight loss. The physical examination findings of marked respiratory distress, crackles in both lung fields, and tachycardia are also consistent with this diagnosis. Laboratory studies reveal anemia, elevated BUN and creatinine, proteinuria, and hematuria with RBC casts, which are all indicative of renal involvement. Additionally, the positive antimyeloperoxidase titer further supports the diagnosis of microscopic polyangiitis. Goodpasture's disease and granulomatosis with polyangiitis may present with similar symptoms, but the absence of renal involvement and negative c-ANCA titer make them less likely diagnoses. Polyarteritis nodosa typically presents with systemic symptoms and involvement of medium-sized vessels, which is not seen in this case. Cryoglobulinemia is also unlikely as it typically presents with skin manifestations and joint swellings, which are not present here.

Explanation

The most likely diagnosis in this case is microscopic polyangiitis. This is supported by the patient's symptoms of hemoptysis, shortness of breath, fatigue, and unintentional weight loss. The physical examination findings of marked respiratory distress, crackles in both lung fields, and tachycardia are also consistent with this diagnosis. Laboratory studies reveal anemia, elevated BUN and creatinine, proteinuria, and hematuria with RBC casts, which are all indicative of renal involvement. Additionally, the positive antimyeloperoxidase titer further supports the diagnosis of microscopic polyangiitis. Goodpasture's disease and granulomatosis with polyangiitis may present with similar symptoms, but the absence of renal involvement and negative c-ANCA titer make them less likely diagnoses. Polyarteritis nodosa typically presents with systemic symptoms and involvement of medium-sized vessels, which is not seen in this case. Cryoglobulinemia is also unlikely as it typically presents with skin manifestations and joint swellings, which are not present here.

14. Which of the following statements regarding rheumatoid arthritis is true?

There is an association with the class II major histocompatibility complex allele HLA-B27

The earliest lesion in rheumatoid arthritis is an increase in the number of synovial lining cells with microvascular injury

Females are affected three times more often than are males, and this difference is maintained throughout life

Africans and African Americans most commonly have the class II major histocompatibility complex allele HLA-DR4

Titers of rheumatoid factor are not predictive of the severity of rheumatoid arthritis or its extraarticular manifestations

The earliest lesion in rheumatoid arthritis is an increase in the number of synovial lining cells with microvascular injury. This means that the first observable change in the development of rheumatoid arthritis is an increase in the number of cells that line the synovial membrane, which surrounds and lubricates the joints. Additionally, there is microvascular injury, which refers to damage to the small blood vessels in the affected area. This statement accurately describes the initial pathological changes that occur in rheumatoid arthritis.

Explanation

The earliest lesion in rheumatoid arthritis is an increase in the number of synovial lining cells with microvascular injury. This means that the first observable change in the development of rheumatoid arthritis is an increase in the number of cells that line the synovial membrane, which surrounds and lubricates the joints. Additionally, there is microvascular injury, which refers to damage to the small blood vessels in the affected area. This statement accurately describes the initial pathological changes that occur in rheumatoid arthritis.

15. A 63-year-old woman is evaluated during a follow-up visit for a 4-week history of fatigue; pain in the proximal interphalangeal joints, knees, and hips; and low-grade fever. She has not had joint swelling, chest pain, or shortness of breath. Over the past 4 years, she has had progressive dryness of the eyes and mouth. She has a 5-month history of Raynaud phenomenon, which has been less symptomatic since beginning nifedipine 4 months ago. On physical examination, temperature is 38.2 °C (100.8 °F), blood pressure is 125/72 mm Hg, pulse rate is 74/min, and respiration rate is 18/min. Cardiac examination is normal, and the lungs are clear. She has bilateral parotid gland enlargement, a firm 4-cm left axillary lymph node, and a shotty 0.3-cm left anterior cervical lymph node. Musculoskeletal examination reveals bilateral crepitus of the knees. There is no joint swelling. Laboratory studies: Hemoglobin 11.6 g/dL (116 g/L) Leukocyte count 3400/µL (3.4 m 109/L) Platelet count 120,000/µL (120 m 109/L) Rheumatoid factor 76 U/mL (76 kU/L) Antinuclear antibodies Positive Anti-Ro/SSA antibodies Positive Anti-La/SSB antibodies Positive Urinalysis Normal Blood cultures No growth A chest radiograph and mammogram are normal. Which of the following is the next best step in this patient's management?

Excisional axillary lymph node biopsy

Minor salivary gland biopsy

Prednisone

Transthoracic echocardiography

The patient presents with a 4-week history of fatigue, joint pain, low-grade fever, and a history of dryness of the eyes and mouth. On examination, she has bilateral parotid gland enlargement and lymphadenopathy. Laboratory studies show leukopenia, thrombocytopenia, positive rheumatoid factor, and positive antinuclear antibodies, anti-Ro/SSA antibodies, and anti-La/SSB antibodies. These findings are consistent with the diagnosis of Sjögren syndrome. Excisional axillary lymph node biopsy is the next best step to evaluate the lymphadenopathy and rule out lymphoma, which can occur in patients with Sjögren syndrome.

Explanation

The patient presents with a 4-week history of fatigue, joint pain, low-grade fever, and a history of dryness of the eyes and mouth. On examination, she has bilateral parotid gland enlargement and lymphadenopathy. Laboratory studies show leukopenia, thrombocytopenia, positive rheumatoid factor, and positive antinuclear antibodies, anti-Ro/SSA antibodies, and anti-La/SSB antibodies. These findings are consistent with the diagnosis of Sjögren syndrome. Excisional axillary lymph node biopsy is the next best step to evaluate the lymphadenopathy and rule out lymphoma, which can occur in patients with Sjögren syndrome.

16. A 64-year-old man with congestive heart failure presents to the emergency room complaining of acute onset of severe pain in his right foot. The pain began during the night and awoke him from a deep sleep. He reports the pain to be so severe that he could not wear a shoe or sock to the hospital. His current medications are furosemide, 40 mg twice daily, carvedilol, 6.25 mg twice daily, candesartan, 8 mg once daily, and aspirin, 325 mg once daily. On examination, he is febrile to 38.5°C. The first toe of the right foot is erythematous and exquisitely tender to touch. There is significant swelling and effusion of the first metatarsophalangeal joint on the right. No other joints are affected. Which of the following findings would be expected on arthrocentesis?

Glucose level of >25 mg/dL

Positive Gram stain

Presence of strongly negatively birefringent needle-shaped crystals under polarized light microscopy

Presence of weakly positively birefringent rhomboidal crystals under polarized light microscopy

White blood cell (WBC) count >100,000/uL

The patient's presentation is consistent with acute gouty arthritis, which is caused by the deposition of monosodium urate crystals in the joint. The presence of weakly positively birefringent rhomboidal crystals under polarized light microscopy is characteristic of gout. The other options are not associated with gout and are not expected findings on arthrocentesis in this case.

Explanation

The patient's presentation is consistent with acute gouty arthritis, which is caused by the deposition of monosodium urate crystals in the joint. The presence of weakly positively birefringent rhomboidal crystals under polarized light microscopy is characteristic of gout. The other options are not associated with gout and are not expected findings on arthrocentesis in this case.

April 2012 Rheumatology Quiz