Purple Urine Bag Syndrome: An Educational Case of a Colorful Condition in the Chronically Catheterized

Abstract

Purple Urine Bag Syndrome is a rare condition characterized by purple discoloration of the urinary drainage bag. It is typically seen in elderly patients with chronic indwelling urinary catheterization, and is associated with urinary tract infections with high bacterial load, female gender, severe disability, constipation, and alkaline urine. This phenomenon occurs when tryptophan metabolites in the urine are broken down by bacteria containing indoxyl sulphatase and phosphatase enzymes. This results in the production of indigo and indirubin, which combine to give a purple appearance. This article presents a 78-year-old male with chronic urinary retention requiring intermittent Foley catheterization for the last three months, who was brought to the Emergency Department for altered mental status and purple urinary bag discoloration. Urinalysis was suggestive of urinary tract infection, and Vancomycin, Aztreonam, and Levaquin were initiated. After urine culture and antibiotic susceptibility testing, only Levaquin was continued, and subsequently the patient’s symptoms resolved. This case serves to educate healthcare professionals in West Virginia about this condition, which we hope will benefit in its diagnosis, management, and targeted prevention, especially in light of an aging population.

Keywords

• purple urine bag syndrome
• catheter-associated urinary tract infection
• tryptophan
• geriatrics
• nursing home care