Prepatellar bursitis: a unique presentation of tophaceous gout in an normouricemic patient.

We describe a patient with no history of gout and persistently normal serum uric acid concentrations in whom septic acute prepatellar bursitis was diagnosed initially, but empiric antibiotic therapy failed. Urate crystals were detected when the prepatellar bursa was aspirated for the 3rd time, and the diagnosis was changed to gouty bursitis. The case illustrates the importance of repeatedly aspirating suspicious sites to establish the diagnosis in elusive cases of crystal deposition disease.