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White Urine in an Asymptomatic Child

      A 5-year-old boy was referred for evaluation of “white-colored, milky urine.” The boy’s mother reported 10 to 12 episodes of white-colored urine occurring during the previous 18 months. She described finding drops of the white-colored urine dried on his underwear that appeared white and crusty, like “dried Maalox.” The boy was otherwise healthy, with no significant past medical history or family history.
      A physical examination was entirely unremarkable. Initial laboratory examination of blood and urine, including electrolytes, blood urea nitrogen, creatinine, parathyroid hormone, vitamin D studies, alkaline phosphatase, and urine protein, was unremarkable aside from an elevated urinary calcium-to-creatinine ratio of 0.36 mg/mg. His urine stain with Sudan was negative for fat, ruling out chyluria. The urine was initially cloudy (Figure, A). After the urine was allowed to sit for 30 minutes, a precipitate settled at the bottom of the sample that was cleared after acidification with hydrochloric acid (Figure, B and C). Renal ultrasonography was unremarkable. A 24-hour urine collection revealed hypercalciuria, as well as elevated supersaturations of calcium phosphate and calcium oxalate. A pellet from the patient’s spun-down urine was found to be 80% brushite and 20% basic calcium phosphate.
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      FigureA, Urine collected while the child was eating a typical low-sodium, low-fat diet, revealing cloudy urine. B, Precipitation of the sample after it was left to sit for 30 minutes. C, Clear appearance of the same sample after the addition of hydrochloric acid.
      The evaluation of albinuria has been described in the literature, but this is the first reported description of cloudy white urine due to mineral precipitation in a child. White urine is most often secondary to chyluria, which results from an aberrant communication between the urinary tract and lymphatic system, commonly due to filariasis.
      • Vera M.
      • Molano A.
      • Rodriguez P.
      Turbid white urine.
      Although hypercalciuria is common in children and can result in crystalluria, hematuria, dysuria, abdominal or back pain, or nephrolithiasis,
      • Srivastava T.
      • Schwaderer A.
      Diagnosis and management of hypercalciuria in children.
      it rarely presents as a white, powdery precipitate in children.
      Given that our patient was asymptomatic, we recommended conservative treatment to minimize his calciuria and mineral supersaturation, consisting of a low-sodium diet with no other restrictions, as well as a water intake of 1 to 1.5 L/day.

      References

        • Vera M.
        • Molano A.
        • Rodriguez P.
        Turbid white urine.
        NDT Plus. 2010; 3: 45-47
        • Srivastava T.
        • Schwaderer A.
        Diagnosis and management of hypercalciuria in children.
        Curr Opin Pediatr. 2009; 21: 214-219