GOUTY ARTHRITIS Flashcards
Which of the following clinical features is most characteristic of gout?
A. Symmetrical polyarthritis affecting small joints
B. Episodic inflammatory arthritis with disabling pain, commonly involving the first metatarsophalangeal joint
C. Chronic low-grade arthritis without acute flares
D. Persistent fever and rash accompanying joint pain
B. Episodic inflammatory arthritis with disabling pain, commonly involving the first metatarsophalangeal joint
Rationale:
Gout commonly manifests as episodic inflammatory arthritis with severe pain, typically involving the first metatarsophalangeal joint (podagra) in 70–90% of cases. It is usually asymmetrical and involves acute flares that resolve spontaneously.
A 58-year-old man presents with acute monoarthritis of the first metatarsophalangeal joint. Joint aspiration reveals needle-shaped crystals with strong negative birefringence under polarized light. Which of the following is the most likely diagnosis?
A. Rheumatoid arthritis
B. Gout
C. Pseudogout
D. Septic arthritis
B. Gout
Rationale:
The presence of needle-shaped monosodium urate (MSU) crystals with negative birefringence on joint aspiration is diagnostic of gout. Pseudogout involves calcium pyrophosphate crystals, while septic arthritis would show no crystals but rather bacteria and elevated WBC.
A patient with gout is starting urate-lowering therapy with allopurinol. Which of the following is the appropriate starting dose, and why?
A. 800 mg daily to quickly lower serum urate levels
B. 100 mg daily or less to minimize the risk of acute gout flares
C. 300 mg daily with colchicine to prevent tophi formation
D. 500 mg daily to normalize serum urate within a week
B. 100 mg daily or less to minimize the risk of acute gout flares
Rationale:
Allopurinol should be started at a low dose (100 mg daily or less) and titrated gradually to minimize the risk of acute gout flares, which often occur with rapid urate reduction.
Which of the following medications is the most appropriate for treating an acute gout flare in a patient with chronic kidney disease?
A. Indomethacin
B. Naproxen
C. Colchicine (low-dose regimen)
D. High-dose colchicine
C. Colchicine (low-dose regimen)
Rationale:
Low-dose colchicine is effective for treating acute gout flares and safer for patients with chronic kidney disease compared to NSAIDs, which are contraindicated in kidney disease, and high-dose colchicine, which increases toxicity risk.
A 60-year-old man with chronic gouty arthritis and visible tophi presents for management. His current uric acid level is 8.5 mg/dL. What is the target uric acid level to prevent further MSU deposition and eliminate tophi?
A. <7.0 mg/dL
B. <6.0 mg/dL
C. <5.0 mg/dL
D. <4.0 mg/dL
B. <6.0 mg/dL
Rationale:
The goal of urate-lowering therapy in gout is to maintain a serum uric acid level below the subsaturation point (<5.0–6.0 mg/dL) to prevent further monosodium urate crystal deposition and promote tophi resolution.
Which of the following is TRUE about the use of febuxostat for gout management?
A. It is a uricosuric agent that requires good renal function for efficacy.
B. It requires dose adjustment in patients with chronic kidney disease.
C. It is contraindicated in patients carrying the HLA-B*5801 allele.
D. It is a xanthine oxidase inhibitor metabolized predominantly in the liver.
D. It is a xanthine oxidase inhibitor metabolized predominantly in the liver.
Rationale:
Febuxostat is a xanthine oxidase inhibitor metabolized predominantly in the liver. It does not require dose adjustment in moderate to severe CKD and is an alternative for patients intolerant to allopurinol.
What imaging feature is most characteristic of advanced gout?
A. Joint space narrowing without erosions
B. Periarticular osteopenia
C. Well-defined erosions with sclerotic margins and overhanging edges
D. Soft tissue calcifications
C. Well-defined erosions with sclerotic margins and overhanging edges
Rationale:
Advanced gout is characterized radiographically by well-defined erosions with sclerotic margins, often with overhanging bony edges, due to the deposition of monosodium urate crystals.
A 58-year-old male with a history of hyperuricemia presents with sudden, severe pain and swelling in his right great toe. On examination, the joint is erythematous, warm, and swollen. Synovial fluid analysis is performed, revealing intracellular and extracellular needle-shaped crystals under polarized light microscopy showing bright, negative birefringence. What is the most likely diagnosis and what is the expected synovial fluid finding?
A) Pseudogout, rhomboid-shaped crystals with positive birefringence
B) Septic arthritis, positive Gram stain with white blood cells >50,000/μL
C) Gout, monosodium urate crystals with negative birefringence
D) Osteoarthritis, no crystals in the synovial fluid
C) Gout, monosodium urate crystals with negative birefringence
Rationale:
The patient’s clinical presentation of sudden, severe pain and swelling in the great toe, along with the finding of monosodium urate (MSU) crystals showing negative birefringence under polarized light, is characteristic of gout.
C (Gout) is the correct answer because it matches the clinical and synovial fluid findings described.
A (Pseudogout) involves calcium pyrophosphate crystals which are rhomboid in shape and show positive birefringence under polarized light.
B (Septic arthritis) would typically present with a high white blood cell count (>50,000/μL) and would show bacteria on Gram stain, not crystals.
D (Osteoarthritis) typically does not have any crystals in the synovial fluid and does not present with this degree of acute inflammation.
A 58-year-old male presents with acute pain, swelling, and redness of his right great toe. He has a history of recurrent gout attacks. His serum urate level is measured at 9.8 mg/dL during the acute attack. Which of the following is the most appropriate long-term management strategy to prevent future gout attacks?
A) Increase the dose of NSAIDs during flares
B) Start a urate-lowering therapy such as allopurinol
C) Administer intra-articular glucocorticoids
D) Continue the patient’s current NSAID regimen during flares only
B) Start a urate-lowering therapy such as allopurinol
Rationale:
B (Start a urate-lowering therapy such as allopurinol) is the correct answer. Long-term management of gout aims to lower serum urate levels to prevent future flares and complications. Allopurinol is the most commonly used urate-lowering therapy, and it should be started after the acute flare resolves.
A (Increase the dose of NSAIDs during flares) is not a long-term solution but rather an acute treatment approach. NSAIDs are used for symptom control during a flare, not for chronic management.
C (Administer intra-articular glucocorticoids) may help in managing acute flares but does not address long-term prevention of gout.
D (Continue the patient’s current NSAID regimen during flares only) is incorrect as it only manages acute attacks and does not prevent future gout flares.
A 55-year-old male with a history of obesity, hypertension, and heavy alcohol consumption presents with recurrent episodes of sudden, severe pain in his big toe, along with redness and swelling. His serum urate level is 9.0 mg/dL. The patient has had two or more gout flares per year for the past three years. Which of the following is the most appropriate next step in management?
A) Prescribe colchicine for acute flare and initiate urate-lowering therapy
B) Prescribe corticosteroids for acute flare without initiating long-term therapy
C) Advise the patient to reduce alcohol intake and reassess in 6 months
D) Increase fluid intake and prescribe NSAIDs only
A) Prescribe colchicine for acute flare and initiate urate-lowering therapy
Rationale:
This patient has a history of recurrent gout flares (more than two attacks per year), which warrants the initiation of urate-lowering therapy (ULT). The goal of ULT is to lower the serum urate level below the subsaturation point (<300-360 μmol/L or 5.0–6.0 mg/dL) to prevent future flares and to eliminate tophi. Colchicine or NSAIDs should be used for managing acute flares, while long-term therapy with urate-lowering medications such as allopurinol or febuxostat should be started in patients with frequent flares or chronic tophi.
Which of the following is a significant risk factor for severe cutaneous adverse reactions (SCARs) to allopurinol?
A) Male sex
B) Lower age
C) HLA-B*5801 carriage
D) Use of febuxostat
C) HLA-B5801 carriage
Rationale: HLA-B5801 carriage is a significant risk factor for SCARs to allopurinol, and screening for this allele is recommended before starting allopurinol in certain ethnic groups such as Southeast Asians, Pacific Islanders, Native Hawaiians, and blacks. This is because these populations have a higher carriage rate of HLA-B*5801, increasing the risk of severe reactions.
Which of the following is the most appropriate action for a patient with the HLA-B*5801 allele before initiating allopurinol?
A) Increase the dosage of allopurinol
B) Screen for chronic kidney disease (CKD)
C) Use an alternative urate-lowering agent
D) Decrease the dosage of allopurinol
Correct Answer: C) Use an alternative urate-lowering agent
Rationale: If a patient carries the HLA-B*5801 allele, it is recommended to avoid starting allopurinol and instead use an alternative urate-lowering agent due to the increased risk of severe cutaneous adverse reactions (SCARs).
C) Use an alternative urate-lowering agent
Rationale: If a patient carries the HLA-B*5801 allele, it is recommended to avoid starting allopurinol and instead use an alternative urate-lowering agent due to the increased risk of severe cutaneous adverse reactions (SCARs).
Which of the following is a true statement regarding febuxostat as an alternative to allopurinol?
A) Febuxostat requires dose adjustment in patients with moderate to severe chronic kidney disease (CKD).
B) Febuxostat is not effective for patients carrying the HLA-B*5801 allele.
C) Febuxostat is metabolized by glucuronide formation and oxidation in the liver.
D) Febuxostat should not be used in patients with kidney problems.
C) Febuxostat is metabolized by glucuronide formation and oxidation in the liver.
Rationale: Febuxostat is primarily metabolized in the liver by glucuronide formation and oxidation, and it is considered safe for use in patients with moderate to severe CKD without the need for dose adjustment. Additionally, it can be used in patients who carry the HLA-B*5801 allele, unlike allopurinol.
Which of the following joints is most commonly affected by acute CPP crystal arthritis (pseudogout)?
A) First metatarsophalangeal joint
B) Knee
C) Elbow
D) Shoulder
B) Knee
Rationale: The knee is the most commonly affected joint in acute CPP crystal arthritis, followed by the wrist. The first metatarsophalangeal joint (podagra) is rarely involved in CPP crystal arthritis, distinguishing it from gout.
Which of the following clinical features is commonly seen in acute CPP crystal arthritis but not in typical gout flares?
A) Elevated serum uric acid
B) Affected first metatarsophalangeal joint (podagra)
C) Systemic signs like fever and chills
D) Presence of tophi
C) Systemic signs like fever and chills
Rationale: Acute CPP crystal arthritis may present with systemic signs such as fever, chills, and elevated acute-phase reactants, which are less common in typical gout flares. This systemic involvement is a distinguishing feature of acute CPP crystal arthritis.
What is the most definitive diagnostic method for acute CPP crystal arthritis?
A) Elevated serum calcium levels
B) Joint biopsy
C) Detection of rhomboid or rodlike crystals in synovial fluid
D) X-ray findings of chondrocalcinosis
C) Detection of rhomboid or rodlike crystals in synovial fluid
Rationale: The definitive diagnosis of acute CPP crystal arthritis requires the demonstration of typical rhomboid or rodlike crystals in synovial fluid or articular tissue, which are generally weakly positively birefringent or nonbirefringent under polarized light.
Which of the following is a potential trigger for an acute episode of CPP crystal arthritis?
A) High serum uric acid levels
B) Parathyroidectomy
C) Alcohol consumption
D) Cold weather exposure
B) Parathyroidectomy
Rationale: Acute CPP crystal arthritis can be precipitated by events such as trauma, severe illness, or surgery, particularly parathyroidectomy. This surgery leads to a rapid decrease in serum calcium and magnesium levels, which can trigger the dissolution and shedding of CPP crystals.
In the absence of joint effusion or indications for synovial biopsy, what is presumptive evidence of CPP crystal arthritis?
A) Elevated serum calcium levels
B) Chondrocalcinosis
C) Joint inflammation on MRI
D) Hyperuricemia
B) Chondrocalcinosis
Rationale: Chondrocalcinosis, which refers to the deposition of calcium pyrophosphate crystals in cartilage, is considered presumptive evidence of CPP crystal arthritis in the absence of joint effusion or indications for synovial biopsy. This radiographic finding suggests the presence of CPPD, though it is not definitive without confirmation of crystals in the synovial fluid.
