Internal Medicine EOR Exam Review |144questions| with correct answers

A 72 y/o man develops severe pain and swelling in both knees, shortly after undergoing an abd hernia repair Sgx. PEx shows warmth and swelling of both knees with large effusions. Arthrocentesis of the right knee reveals the presence of intracellular and extracellular weakly positive birefringent crystals in the synovial fluid. Gram stain is negative. Which of the following is the most likely diagnosis? A. Gout B. Septic arthritis C. Calcium oxalate deposition disease D. Reactive arthritis E. Pseudogout CORRECT ANSWER The correct answer is E. Explanation: Pseudogout is diagnosed by positive birefringent crystals. Arthrocentesis revealing needle-shaped, negatively birefringent crystals would be more consistent with gout. Septic arthritis is more likely to present as a monoarticular arthritis and synovial fluid will be filled with WBCs often with a left shift rather than crystals. A 65-year-old man with a history of chronic hypertension, diabetes mellitus, and degenerative joint disease presents with acute onset of severe pain of the metatarsophalangeal (MTP) joint and swelling of the left first toe. Physical examination shows exquisite tenderness of the joint, with swelling, warmth, and erythema. The patient has no history of trauma or other significant medical problems. Synovial fluid analysis and aspiration are most likely to show which of the following? A. Hemorrhagic fluid B. Needle-shaped, negatively birefringent crystals C. Gram-negative organisms D. Noninflammatory fluid E. Rhomboidal, positively birefringent crystals CORRECT ANSWER The correct answer is B. Explanation: The involvement of the great toe is most likely gout, and the synovial fluid is likely to show needle-shaped, negatively birefringent crystals.