A rare case of BK cystitis in an immunocompetent patient.

Hemorrhagic cystitis secondary to BK virus is often seen in immunocompromised patients, but it is a rare cause of hematuria or hemorrhagic cystitis in immunocompetent children. We report a case of an otherwise healthy 4-year-old female who presented to urgent care for urinary frequency, dysuria, and gross hematuria. The initial hematuria workup, including complements, anti-nuclear antibody, anti-streptolysin O titer, and urine culture, was all negative. However, hematuria persisted for 14 days and further work up showed viral PCRs that were positive for BK virus both in blood and urine.