Purple Urine Bag Syndrome: A Rare Clinical Entity in a Female Patient with a Long-term Indwelling Urethral Catheter

Abstract

Background: Discoloration of urine is commonly encountered in clinical practice and this at times may indicate significant pathology. Nevertheless, the majority of instances are benign. Blue and purple dye discoloration of the urinary catheter drainage system israre and can be alarming to both patients and health care workers who are not aware of the condition which is called Purple-Urine-Bag-Syndrome (PUBS). PUBS, is associated with urinary tract infections occurring in catheterised patients, generally elderly females with significant co-morbidities and constipation. The urine is usually alkaline. Gram-negative bacteria that produce sulfatase and phosphatase are involved in the formation of pigment, indigo which gives a blue coloration and indirubin which gives a purple coloration. Tryptophan metabolism is involved in the pathogenesis. Case Report: A 60-year-old lady who had a long-term urethral catheter for four years went to see her General Practitioner on few occasions with a report that her urine has been draining blue dye into her urine bag which was followed by drainage of purple dye into the catheter bag. The General practitioner did not know the cause of the problem but gave the patient antibiotic on each occasion and the blue/purple dye urine discoloration cleared each time she was given empirical antibiotic treatment. Her urine culture grew E coli at the time of the discoloration.Conclusion: PUBS occurs in long-term catheterised patients; is associated with UTI; presents with symptom-less blue/purple discoloration of urine; resolves with appropriate antibiotic treatment.