A. 68-year-old man presents with an acutely red and swollen right great toe with out history of trauma. Which of the following findings is most useful for making a diagnosis of gout in this patient?

The most specific way to make a diagnosis of acute gout is to aspirate the involved joint and to identify negatively birefringent, needle shaped crystals under red-compensated polarized light. The next best way to make a diagnosis of gout is to give oral colchicine hourly until the patient develops significant improvement in joint inflammation or gastrointestinal side effects that prevent fuher colchicine use. Rarely do patients with other diagnoses respond to colchicine trial. The other tests are too nonspecific to be of diagnostic use.