Epidemiology and Risks of Red Urine in Patients in the Pediatric Emergency Department of a Medical Center in Central Taiwan: An 8-Year Study

Background: Red urine, an uncommon presentation in the pediatric emergency room, can be categorized into pigmenturuia and gross hematuria. Pigmenturia has been associated with a number of conditions, including colored foods and crystals. However, gross hematuria results from different causes and presents different risks in adults than in children. Glomerulopathies, the incomplete clearing of substances from the blood that make their way through the glomerulus to urine, can progress to end-stage renal failure if not detected and treated early. Therefore, this study undertook a retrospective analysis of all pediatric patients who presented red urine at the pediatric emergency department of Changhua Christian Hospital between June 2000 and June 2007 to determine the proportion of red urine, analyze probable etiologies and investigate the factors associated with the development of glomerulonephritis in this population.Methods: We reviewed and analyzed 180 medical charts of children with red urine and tested our results using two-sample t-test and Pearson product-moment correlation coefficient.Results: Almost 1/1000 (0.9/1,000) children visiting the pediatric emergency room presented red urine during the study period. Gross hematuria and pigmenturia patients were significantly different in age (6.10 ±3.37SD vs. 3.06 ±3.35SD, respectively; p=＜0.001. The most common underlying cause was urinary tract infection (36.7%). Glomerulonephritis occurred in 10.2% of all the patients. There was a significant difference in C-reactive protein concentrations in glomerulonephritis patients and non-glomerulonephritis patients. Cases with recurring red urine and proteinuria were significantly more likely to have glomerulonephritis.Conclusion: Red urine is relatively uncommon (0.9/1,000) in children visiting the emergency room. Glomerulonephritis was found in 10.2% of patients presenting with red urine. Patients with red urine who had a history of recurrence or proteinuria were a greater risk of glomerulonephritis.