CKD patients found that the urine turned purple, but was misdiagnosed as hematuria

Purple urine bag syndrome is an uncommon symptom that is generally thought to be related to urinary tract infections
.

Although similar symptoms have been reported many times, there are still misdiagnosis and improper management, and the patient's body and mind are greatly affected
.

 In August 2021, a doctor at the Yarmouk University School of Medicine in Jordan found that an 80-year-old woman with type 2 diabetes, chronic kidney disease (CKD) stage 5, hypertension, and ischemic stroke had a purple urine bag.
Syndrome
.

So, what does it mean to have purple urine bag syndrome in CKD patients? Is the situation serious? What kind of treatment is needed? Case profile The patient is an 80-year-old woman with type 2 diabetes, chronic kidney disease (CKD) stage 5, hypertension, and ischemic stroke
.

She relied on a wheelchair to move due to dislocation and weakness of her lower limbs
.

Due to incontinence, she was treated with an indwelling catheter.
It is worth noting that she has a history of recurrent urinary tract infections
.

One month before the visit, the catheter was changed for the last time
.

When seeing a doctor, the medical staff found that the color of the urine in the urine bag was purple
.

 The main complaint of the patient: Constipation, but denied fever, chills or abdominal pain
.

Re-examination of the remaining symptoms was not significant
.

 Patient medication history: amlodipine 5mg/d, bisoprolol 5mg/d, furosemide 40mg/d, sodium bicarbonate 1000mg/d, ferrous gluconate 300mg/d, insulin 2 times/d
.

 The patient was accompanied by pitting edema of the lower extremities, and the rest of the cardiopulmonary examinations were normal
.

 Two days before the consultation, doctors at other medical institutions thought the above symptoms were hematuria, but doctors at the Yarmouk University School of Medicine in Jordan thought it was a misdiagnosis
.

 After changing the catheter, the patient started taking antibiotics and laxatives, and the doctor sent a urine sample for urinalysis and urine culture
.

The results showed that the urine pH was 8.
0, the glucose was negative, the white blood cell count was 8-10/HPF, and the red blood cell count was 3-5HPF
.

Urine culture showed that Proteus mirabilis grew in large numbers and was sensitive to amoxicillin/clavulanic acid, ceftriaxone and ciprofloxacin
.

 After retrieving her medical records, it was discovered that the patient had undergone a urine culture 6 weeks before this visit, and found that she had E.
coli
.

Serum creatinine is 328 μmol/L (normal range is 40-80), urea is 30.
2mmol/L (normal 2.
8-8.
9), phosphate is 1.
68mmol/L (normal 0.
84-1.
45), the above three indicators are all elevated , And other indicators are within the normal range
.

 So the doctor asked the patient to take ciprofloxacin (500mg/tablet, one tablet daily for 5 days)
.

After a week, the patient's urine returned to normal.
The doctor recommended that the catheter should be replaced every month to reduce the risk of urinary tract infection
.

Discussion In 1798, Barlow et al.
reported the purple urine bag syndrome for the first time
.

This type of disease is relatively rare and is usually associated with urinary tract infections and urinary catheters.
It is often misdiagnosed as hematuria at the initial stage, so the wrong treatment is used
.

 CKD patients are not a high-risk group of purple urine bag syndrome, but compared with the general population, patients with advanced CKD (renal failure) are more likely to develop purple urine bag syndrome
.

The reason is that the patient's uremic toxins accumulate in the blood, which may lead to an increase in indoxyl sulfate in the urine
.

Phosphatase and sulfatase produced by some bacteria can convert indoxyl sulfate into indolyl
.

Indolyl oxides are red and blue, so they tend to appear purple
.

 In addition, patients with constipation, women, increased tryptophan in their diet, increased urine pH, and indwelling catheters are more likely to have purple urine bag syndrome
.

 Doctors from Yarmouk University School of Medicine have suggested that changes in urine color can be caused by many reasons, such as toxic substances, food colors, drugs, urinary tract infections, urinary stones, hematuria, hemoglobinuria, and porphyria
.

  Summary In general, purple urine bag syndrome is a rare disease that is easily misdiagnosed
.

This can lead to incorrect management and unnecessary inspections
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Physicians need to be aware of this phenomenon in order to provide patients with appropriate care
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References: 1.
SarairehM, Gharaibeh S, Araydah M, et al.
Violet discoloration of urine: A case report and a literature review.
Ann Med Surg (Lond).
2021 Jul 16;68:102570.
eCollection2021 Aug.