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Year : 2019  |  Volume : 8  |  Issue : 1  |  Page : 67-68

The purple urinary bag syndrome – Be alerted, not alarmed!

1 Department of Medicine, JSS Medical College and Hospital, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
2 Department of Obstetrics and Gynaecology, JSS Medical College and Hospital, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
3 Consultant Physician, Tokas Hospital, Jaipur, India

Date of Submission03-Sep-2018
Date of Acceptance21-Jan-2019
Date of Web Publication26-Apr-2019

Correspondence Address:
Dr. Mahesh Mahadevaiah
B-106 Brigade Solitaire Apartments, Alanahally Layout, Mysore - 570028, Karnataka
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Source of Support: None, Conflict of Interest: None


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Purple-appearing urinary catheter and urosac can be alarming to the patient's attenders and doctors. It may be misinterpreted and overinvestigated if the underlying causes and mechanisms of this phenomenon are not understood. Urinary tract infection with sulfatase- and phosphatase-producing bacteria is implicated in the pathogenesis. We hereby report the appearance of purple color of urinary bag and catheter in an elderly female patient with dementia and chronic paraplegia on long-term Foley's catheterization.

Keywords: Foley's catheter, urinary catheterization, urinary infection

How to cite this article:
Mahadevaiah M, Shivanagappa M, Jain S. The purple urinary bag syndrome – Be alerted, not alarmed!. J NTR Univ Health Sci 2019;8:67-8

How to cite this URL:
Mahadevaiah M, Shivanagappa M, Jain S. The purple urinary bag syndrome – Be alerted, not alarmed!. J NTR Univ Health Sci [serial online] 2019 [cited 2020 Mar 31];8:67-8. Available from: http://www.jdrntruhs.org/text.asp?2019/8/1/67/257171

  Introduction Top

The term “purple urinary bag syndrome” (PUBS) refers to the purplish coloration of the urinary catheter and urosac that is occasionally noticed in patients on chronic urinary catheterization. Commonly, this is seen in those with associated constipation, dementia, and urinary tract infection. This is usually a benign condition. But if not recognized correctly by the attending clinician, it may lead to unnecessary investigations and therapies. A typical case of PUBS is reported herewith.

  Case Report Top

An 85-year-old female was brought by her relatives with history of fever with chills since 1 week. She was a known case of dementia and paraparesis for the last 6 years and since then she was bedridden and on chronic catheterization with Foley's catheter.

On examination, she had moderate dehydration. There was tachycardia and tachypnea. She was afebrile. Her blood pressure was 150/90 mmHg. Systemic examination revealed dementia and presence of chronic paraplegia with contractures. On the third day of admission, it was noted that the Foley's catheter and urosac bag had a characteristic purple color [Figure 1] and [Figure 2].
Figure 1: Purplish color of the urinary bag and Foley's catheter

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Figure 2: Close-up view of the urosac. Also note the clear urine in the small bottle obtained from the catheter

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The urine obtained by emptying the bag and collected directly from Foley's catheter was noted to be clear without any purplish color. Urinary microscopy examination for pus cells revealed significant numbers of pus cells. The patient was started on antibiotic therapy with quionolones. She made a good recovery with respect to the urinary infection and there was no purplish color of the replaced catheter and urosac thereafter.

  Discussion Top

PUBS was first described 35 years ago.[1] A relatively rare condition, it refers to the purplish discoloration of the urinary catheter and urosac. It is more often seen in elderly female patients on chronic catheterization with associated chronic urinary tract infection, dementia, dehydration, and constipation. A prevalence of 8.39% has been reported in patients with long-term urinary catheterization.[2]

Sulfatase- and phosphatase-producing bacteria are implicated in the pathogenesis.[3] Bacterial species such as Pseudomonas aeuruginosa, Proteus mirabilis,  Escherichia More Details coli, Klebsiella pneumoniae, Providencia rettgeri, and Proteus vulgaris are all implicated in this phenomenon.[4]

However, infection with bacteria of the above species lacking sulfatase and phosphatase does not give rise to this syndrome. The rarity of PUBS despite urinary tract infections being common is because of the above. Constipation increases bacterial overgrowth and is a prominent contributing factor.[5]

The pathophysiological basis is as follows: dietary tryptophan is acted upon by bacteria leading to production of indole which is transported to the liver. There indole is converted to indoxyl sulfate which is excreted in the urine. Bacteria colonizing the urinary catheter convert the indoxyl sulfate to indirubin which is a red pigment and indigo which is blue. The mixture of red and blue appears as purple. A diet high in tryptophan thus increases the chances of developing this syndrome.[5]

A “purple diaper syndrome” has also been recognized recently, and the pathogenesis is similar that of PUBS.[6]

  Conclusion Top

The unusual coloration is certainly alarming, but it serves as a pointer to the presence of an underlying urinary tract infection. Healthcare providers should be aware of this syndrome, and early initiation of antibiotic therapy is indicated. Appropriate therapy for constipation and nutritional changes are equally necessary.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Barlow GB, Dickson JAS. Purple urine bags. Lancet 1978;28:220-1.  Back to cited text no. 1
Hadano Y, Shimizu T, Takada S, Inoue T, Sorano S. An update on purple urine bag syndrome. Int J Gen Med 2012;5:707-10.  Back to cited text no. 2
Harun NS, Muhammad SK, Nainar SH, Chong VH. Purple urine bag syndrome: A rare and interesting phenomenon. South Med J 2007;100:1048-50.  Back to cited text no. 3
Al-Sardar H, Haroon D. Purple urinary bag syndrome. Am J Med 2009;122:e1-2.  Back to cited text no. 4
Bhattarai M, Mukhtar HB, Davis TW, Silodia A, Nepal H. Purple urine bag syndrome may not be benign: A case report and brief review of the literature. Case Rep Infect Dis 2013;2013:863853.  Back to cited text no. 5
Lau CL, Ong KL. An elderly with purple urine. Hong Kong J Emerg Med 2009;16:159-60.  Back to cited text no. 6


  [Figure 1], [Figure 2]


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