LETTER TO THE EDITOR |
https://doi.org/10.5005/jp-journals-10028-1676 |
Purple Urine Bag Syndrome: An Intriguing Presentation
1,2,4Department of General Medicine, Government Medical College & Hospital, Chandigarh, India
3Department of Medicine, Sri Guru Ram Das University of Health Sciences, Amritsar, Punjab, India
Corresponding Author: Ambadas Rathod, Government Medical College & Hospital, Chandigarh, India, Phone: +91 7989799724, e-mail: ambadasrathod100@gmail.com
How to cite this article: Rathod A, Cheema YS, Kaur H, et al. Purple Urine Bag Syndrome: An Intriguing Presentation. J Postgrad Med Edu Res 2024;58(3):149-150.
Source of support: Nil
Conflict of interest: None
To the Editor,
We are writing to share an intriguing and visually remarkable case of purple urine bag syndrome (PUBS), which can be very alarming to the patient as well as the treating physician due to its striking visual presentation. It is an uncommon condition often associated with urinary tract infections (UTIs) and prolonged catheterization. This communication highlights the key aspects of pathogenesis and management of PUBS by presenting a recent case we encountered, emphasizing its clinical implications for healthcare providers. Recognizing this rare complication is essential to avoid misdiagnosis and erroneous treatment.
A 75-year-old woman presented to the emergency room with a history of hypertension and diabetes, having sustained a fractured neck of the femur following a fall. She had been catheterized for 2 months and reported reduced urine output and constipation for 1 week. Two days prior to the presentation, she noticed purple discoloration in her urine bag. The catheter had been in place for 2 months and had not been changed since the initial catheterization. The urine was clear and exhibited a distinct purple hue (Fig. 1). The patient denied any history suggestive of typical UTI symptoms such as fever, dysuria, chills, rigors, or suprapubic pain.
Fig. 1: Purple urine bag
Physical examination revealed no suprapubic or renal angle tenderness. Urine microscopic examination showed significant leukocyturia with a pH of 6. A fresh catheter and urine bag were placed, and a urine sample was sent for culture and sensitivity. Empirical antibiotic therapy with piperacillin + tazobactam was initiated. The urine culture grew Pseudomonas aeruginosa, sensitive to multiple antibiotics including piperacillin–tazobactam. After 4 days of parenteral therapy, the purple discoloration resolved. Intravenous therapy with piperacillin–tazobactam was continued for a total of 14 days with full recovery.
Purple urine bag syndrome was first reported in 1978. The reported prevalence of PUBS is 8.3–16.7% in patients with long-term urinary catheterization. PUBS usually appears after about 2–3 months of catheterization. It is most frequently observed in elderly female patients who suffer from chronic constipation and prolonged catheterization, especially in bedridden state. It has been reported with both per-urethral and suprapubic catheterization. Risk factors for PUBS include factors such as alkaline urine, female gender (with a heightened risk due to a shorter urethra), and chronic constipation (decreased intestinal motility leads to bacterial overgrowth leading to an increase in metabolism of tryptophan to indole, which in turn results in high levels of indigo and indirubin in the urine). Dehydration and chronic renal failure, which leads to reduced clearance of tryptophan metabolites, have also been associated with PUBS.1
While PUBS typically occurs in alkaline urine, in this particular case urine was acidic. Though rare, there have been case reports of PUBS in patients with acidic urine.2 The purple color in urine is believed to come from the pigments indican and indirubin, though there have been reports of PUBS without evidence of indicanuria. The purple color in PUBS results from the metabolism of tryptophan by intestinal bacteria, which convert it into indole. This is then transformed into indoxyl sulfate in the liver. Bacterial enzymes such as phosphatases or sulfatases convert indoxyl sulfate to indoxyl, which in the urine is further converted into indigo and indirubin pigments. Indigo is blue and indirubin is red, combining to give the urine its purple hue.2
The discoloration is benign, harmless and mainly of cosmetic concern, the physician should look for concomitant UTI. Many bacteria have been associated with PUBS, the common ones being Escherichia coli, Enterococcus species, Klebsiella pneumoniae, Providencia stuartii, Providencia rettgeri, Morganella morganii, P. aeruginosa, Proteus mirabilis, Citrobacter species, and Providencia species.3
Purple urine bag syndrome is a benign and harmless condition in most cases and its bearing on morbidity is unclear. Rarely, PUBS can be associated with severe complications such as abscesses or Fournier’s gangrene. Improving urological sanitation and control of constipation by appropriate nutritional management are essential for the prevention of PUBS. Proper hydration, improved catheter care, and hygiene have also been shown to reduce the incidence of PUBS.2 Management of PUBS involves changing the catheter and urine bag. Presence of symptomatic UTI and the occurrence of PUBS in immunocompromised patients’ merits treatment with appropriate antibiotics. Given that patients with prolonged catheterization may not exhibit classic UTI symptoms, PUBS can serve as a critical indicator for underlying infection in these individuals.4
Purple urine bag syndrome is a rare yet visually striking condition that signals underlying UTIs in bedridden, catheterized, and constipated elderly patients. Awareness of this syndrome is essential for primary care physicians to manage and alleviate patient anxiety effectively. This case emphasizes the importance of recognizing PUBS as a benign but indicative condition necessitating prompt medical attention and appropriate antibiotic therapy.
ORCID
Ambadas Rathod https://orcid.org/0009-0000-1868-3020
Yuvraj S Cheema https://orcid.org/0000-0002-5280-1681
REFERENCES
1. Pandey S, Pandey T, Sharma A, et al. Purple urinary bag syndrome: what every primary healthcare provider should know. BMJ Case Rep 2018;2018:bcr2018226395. DOI: 10.1136/bcr-2018-226395
2. Hadano Y, Shimizu T, Takada S, et al. An update on purple urine bag syndrome. Int J Gen Med 2012;5:707–710. DOI: 10.2147/IJGM.S35320
3. Al Montasir A, Al Mustaque A. Purple urine bag syndrome. J Family Med Prim Care 2013;2(1):104–105. DOI: 10.4103/2249-4863.109970
4. Peters P, Merlo J, Beech N, et al. The purple urine bag syndrome: a visually striking side effect of a highly alkaline urinary tract infection. Can Urol Assoc J 2011;5(4):233. DOI: 10.5489/cuaj.10177
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