Eosinophilic Ureteritis in a Child With Ureteropelvic Junction Obstruction and Vesicoureteral Reflux.

Eosinophilic ureteritis is a rare cause of ureteral obstruction, and to date the diagnosis can only be made on pathologic examination. The true underlying cause is not well understood, but there may be some association with eosinophilia, atopy and/or trauma. We present a case of a two-year-old boy with ureteropelvic junction obstruction (UPJO) and ipsilateral vesicoureteral reflux (VUR) found to have eosinophilic ureteritis. To our knowledge, this is the youngest reported patient with this finding, and the only patient with eosinophilic ureteritis causing UPJO with concomitant VUR.