High synovial fluid white blood cell counts in pseudogout; Possible confusion with septic arthritis.

During a 12-month period, we have treated five patients with acute inflammatory arthritis and synovial fluid leukocyte counts of 65,000 to 100,00/cu mm with 93% to 100% polymorphonuclear cells, calcium pyrophosphate dihydrate crystals in the synovial fluid, and negative cultures. Four of these five were origingally treated for septic joints. We would like to emphasize this relatively uncommon, but important manifestation of pseudogout.