Purple urine bag syndrome: report of an unusual case in a patient with a chronic indwelling urinary catheter

Abstract

Purple urine bag syndrome (PUBS) is an infrequent and generally asymptomatic condition characterized by purple discoloration of the urine in patients with an indwelling urinary catheter, secondary to bacterial metabolism of tryptophan and pigment production. We describe the case of an 82-year-old man with a history of benign prostatic hyperplasia, arterial hypertension, and chronic Foley catheter use, who presented for a preoperative consultation without symptoms, reporting purple urine of 48 hours’ duration. Urine culture revealed growth of extended-spectrum β-lactamase producing Klebsiella pneumoniae. Given the
absence of urinary or systemic symptoms, antibiotic therapy was withheld, and only replacement of the urinary drainage system was performed. The patient showed favorable clinical evolution, with resolution of the discoloration. Although striking in appearance, PUBS is a benign finding associated with asymptomatic bacteriuria, and its management should avoid the unnecessary use of antibiotics.