Associated with urine tract infections in catheterized patients.
Patients are usually elderly women with multiple comorbidities.
Prevalence is as high as 9.8% among patients in long-term care facilities.
Common factors or alkaline urine and dehydration.
Patients usually are asymptomatic.
Pathophysiology is that gram-negative bacterial organisms that possess sulfatase or phosphatase convert indican, a tryptophan metabolite, into indirubin and indigo, which produce the urinary pigments.
The catheter drainage bag becomes progressively stained from red to violet by the pigments, while the year in itself is not grossly discolored.