Purple urine bag syndrome as a rare manifestation of urinary tract infection: A case report

Purple urine bag syndrome (PUBS) is purple discoloration of urinary catheter, tubing and bag and it is a rare and uncommon manifestation of urinary tract infection. Female gender, constipation, urinary tract infection, dementia, alkaline urine and high urinary bacterial counts are main risk factors. Here we report a 70 year old woman living in a nursing home presented with diarrhea, decreased oral intake and purple urine. The urine was evaluated and urine analysis showed PH=7 and pyuria. The result of urine culture was growth of more than 100000 colony of Proteus Mirrabilis sensitive to Imipeneme. The patient condition improved after antibiotic therapy. The main reason of this phenomenon is not clearly recognized but some authors believe that Indigo (blue pigment) and Indirubin (red pigment) which are metabolite derivate of tryptophan can cause this uncommon discoloration. This condition is benign without any serious consequences and the treatment of underlying disease should be considered.