title: Purple urine bag syndrome: a rare and interesting phenomenon.
abstract: Discoloration of urine is not uncommonly encountered in clinical practice and may indicate a significant pathology. However, the majority of instances are benign and occur as the result of trauma to the urological system during procedures or ingestions of substances such as medication or food. Purple discoloration of a urinary catheter bag is rare and can be alarming to both patients and healthcare workers. This phenomenon is known as the purple urine bag syndrome. It is associated with urinary tract infections occurring in catheterized patients, generally elderly females with significant comorbidities and constipation. The urine is usually alkaline. Gram-negative bacteria that produce sulfatase and phosphatase are involved in the formation of pigment, indirubin and indigo. Tryptophan metabolism is involved in the pathogenesis. We present two cases of this rare and interesting phenomenon and discuss the underlying pathogenesis.
authors.affiliation: Department of Medicine, Raja Isteri Pengiran Anak Saleha Hospital, Bandar Seri Begawan, BA 1710, Brunei Darussalam.
authors.forename: Noriko Soffi
authors.initials: NS
authors.lastname: Harun
authors.forename: Syed Khader Muhammad Shahul Hameed
authors.initials: SK
authors.lastname: Nainar
authors.forename: Vui Heng
authors.initials: VH
authors.lastname: Chong
mesh_terms: D000368:Aged; D002408:Catheters, Indwelling; D002908:Chronic Disease; D003248:Constipation / Q000150:complications; D003681:Dehydration / Q000150:complications; D004927:Escherichia coli Infections / Q000201:enzymology / Q000652:urine; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007203:Indigo Carmine; D007211:Indoles / Q000652:urine*; D008875:Middle Aged; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D013429:Sulfatases / Q000378:metabolism; D013577:Syndrome; D014546:Urinary Catheterization / Q000295:instrumentation*; D014552:Urinary Tract Infections / Q000652:urine*
chemical_list: D007211:Indoles; D007203:Indigo Carmine; D010744:Phosphoric Monoester Hydrolases; D013429:Sulfatases; C027185:indirubin