A 91-year-old woman arrives by ambulance to the emergency department because she was experiencing severe pain in her right middle finger (Figure 102-1). History reveals that she has had swelling of her finger for approximately 1 year. Palpation of the distal interphalangeal joint demonstrated firmness rather than fluctuance. A radiograph of the finger was ordered (Figure 102-2). The radiograph and physical examination are consistent with acute gouty arthritis superimposed on tophaceous gout. The diagnosis was confirmed by an aspirate of the finger that demonstrated negatively birefringent, needle-like crystals, both intracellularly and extracellularly. She was given 1.2 mg of colchicine followed by a second dose of 0.6 mg after 1 hour. Her pain was markedly decreased in 4 hours. Her serum uric acid level was determined to be 10.7 mg/dL. Colchicine was used in this case because the risk of using nonsteroidal anti-inflammatory drugs (NSAIDs) was considered to be high because of her previous history of gastric bleeding secondary to NSAIDs.
Acute gouty arthritis superimposed on tophaceous gout. (Reproduced with permission from Geiderman JM. An elderly woman with a warm, painful finger, West J Med. 2000;172(1):51-52.)
This X-ray of the finger in Figure 102-1 shows several tophi (monosodium urate [MSU] deposits) in the soft tissue over the third distal interphalangeal joint. Note the typical punched-out lesions under the tophi. This is subchondral bone destruction. (Reproduced with permission from Geiderman JM. An elderly woman with a warm, painful finger, West J Med. 2000;172(1):51-52.)
Gout is an inflammatory crystalline arthritis. Elevated uric acid leads to deposition of monosodium urate (MSU) crystals in the joints resulting in a red, hot, swollen joint. Gout typically begins as a monoarthritis, but can become polyarthritic. Treatment of acute episodes includes NSAIDs, colchicine, or intraarticular steroids. Chronic therapy includes lowering the uric acid level using dietary modifications and urate-lowering drugs.
One-year prevalence of gout in many different countries is approximately 5 per 1000.1
Incidence of gout is approximately 1–2 per 1000 person years.1
Gout is four times more common in men than women until age 65; after age 65, gout is three times more common in men than women.2
Gout usually begins after the age of 30 in men and after menopause in women.
Several polymorphisms that regulate uric acid levels have been associated with increases in risk and severity of gout.2
ETIOLOGY AND PATHOPHYSIOLOGY
Defective uric acid metabolism with inefficient renal urate excretion leads to underexcretion of uric acid and an elevated serum uric acid level.
Overproduction of uric acid, instead of underexcretion, occurs in ...