AANP Family Nurse Practitioner (FNP) Certification ExamAssessmentHard
A 48-year-old male presents with acute onset of severe pain, swelling, and redness in his right great toe, which started overnight. He denies any recent trauma. He has a history of hypertension and occasionally drinks alcohol. On examination, the affected joint is exquisitely tender to touch, warm, and erythematous. What is the most appropriate initial diagnostic test?
- AJoint aspiration and synovial fluid analysis
- BSerum uric acid level
- CX-ray of the foot
- DComplete blood count (CBC)
Show answer & explanationAnswer & explanation
Correct answer: A. Joint aspiration and synovial fluid analysis
The patient's classic presentation of acute monoarticular arthritis of the great toe (podagra) with severe pain, swelling, and erythema is highly suggestive of acute gout. While serum uric acid and X-rays can be supportive, the definitive diagnosis of gout is made by joint aspiration and synovial fluid analysis, which reveals negatively birefringent, needle-shaped urate crystals under polarized light microscopy.
Why the other options are wrong
- B. Serum uric acid levels can be normal during an acute gout attack and are not diagnostic; they are more useful for monitoring long-term management.
- C. An X-ray of the foot may show soft tissue swelling but will not confirm gout and is primarily used to rule out other conditions like fracture or osteomyelitis in atypical presentations.
- D. A CBC may show leukocytosis during an acute inflammatory process but is non-specific and does not confirm the diagnosis of gout.
Acute Gout Diagnosis
The definitive identification of an acute inflammatory arthritis caused by the deposition of monosodium urate crystals in joints.
- Classic presentation: acute, severe monoarticular arthritis, often of the great toe (podagra).
- Exquisitely tender, warm, erythematous joint.
- Diagnosis confirmed by synovial fluid analysis showing negatively birefringent urate crystals.
Memory trick: Great Toe Pain? Get the Fluid, See the Crystals!