A man in surgical ward develops excruciating pain in his right ankle joint, a day after cholecystectomy.

You are asked to see a 50-year-old man in the surgical ward at 6 am who underwent an uncomplicated cholecystectomy for gallstones the day before. He has developed excruciating pain in his left ankle joint. He has a history of angina and hypertension for which he takes bendroflumethiazide (bendrofluazide) and aspirin.
Examination of his cardiovascular and respiratory system is unremarkable, as is his abdomen. His left ankle is red, warm, swollen and tender. Routine blood tests show mildly impaired renal function.

What is the most likely diagnosis?
A. Cellulitis
B. Deep vein thrombosis
C. Septic arthritis
D. Gout
E. Rheumatoid arthritis


Answer:
D--Gout

Discussion: Gout is an abnormality of uric acid metabolism resulting in the deposition of sodium urate crystals in joints, soft tissue and urinary tract. It is due to hyperuricaemia resulting from the
overproduction or under-excretion of uric acid.
It mainly affects men and an acute attack usually begins suddenly in the early hours of the morning. Attacks may be precipitated by a surgical operation, starvation, dietary or alcoholic excess and drugs such as diuretics. It usually attacks the big toe, but the ankle, knee or other toe joints may be affected in 25% of the patients. The joint is typically red, warm and tender.
Aspirating the affected joint and examining the synovial fluid under polarized light microscopy will show long, needle-shaped, negatively birefringent crystals, which is diagnostic. A normal serum uric acid does not exclude the diagnosis of gout. Acute attacks should be treated with an anti-inflammatory drug.