Review Question - QID 101947

The clinical picture and join aspiration are consistent with gout, which results from tissue deposition of monosodium urate crystals due to supersaturation. The crystals are then phagocytized by polymorphonuclear cells, which release inflammatory mediators that cause joint inflammation

Clinically, gout presents with arthritis (gouty arthritis) or tophi (chronic tophaceous gout). Gouty arthritis consists of recurrent attacks of articular and periarticular inflammation. The most common area of the body to be affected is the first toe. Chronic tophaceous gout generally takes many years to develop and can result in a chronically stiff and swollen joints. Tophi are subcutaneous nodules resulting from the deposition of crystals in the subcutaneous tissue.

Illustration A shows the appearance of monosodium urate crystals under polarized light.

Incorrect Answers:
Answer 2: Calcium pyrophosphate deposition disease, also known as pseudogout, is the result of deposition of calcium pyrophosphate crystals. These crystals are rhomboid shaped and weakly positively birefringent.
Answer 3: Gout results from deposition of monosodium urate - not uric acid.
Answer 4: Synovial fluid aspiration in acute tuberculosis arthritis will be non-hemorrhagic, turbid and xanthochromic. The WBC count is moderately elevated with a predominance of polymorphonuclear leukocytes.
Answer 5: Synovial fluid aspiration is not routinely used for diagnosis of rheumatoid arthritis. Analysis may reveal decreased levels of complement factors.