Check out today’s Step 2 CK Qmax Question Challenge.
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A 75-year-old man presents to his family physician with a 3-day history of joint pain. The patient has had various “aches and pains” in his joints over the years, but in the past 3 days he has noticed that his first metatarsophalangeal (MTP) joint in his left foot has become very painful. He describes the pain as a dull, constant ache, 7 of 10 in severity. He denies any recent trauma or exposure to infectious agents. The remainder of his musculoskeletal examination is normal, with full range of motion and no focal tenderness in any of his other joints. The first MTP in the left foot is warm, erythematous, and extremely tender to touch. Synovial fluid presents with elevated WBCs and no RBCs, and a Gram stain is negative. Polarized light microscopy is shown in the image below.
Which of the following is the most likely diagnosis?
A. Acute gout
C. Rheumatoid arthritis
D. Septic arthritis
E. Systemic lupus erythematosus
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