Stenosing hemorrhagic ureteritis in a child with Henoch-Schönlein purpura: CT appearance.

Henoch-Schönlein purpura is rarely considered in the differential diagnosis of ureteral obstruction in children. Renal ultrasound and intravenous urography may reveal hydroureteronephrosis but usually fail to yield a specific diagnosis. In this child CT differentiated between an intrinsic ureteral stenosis (hemorrhagic ureteritis) and an extrinsic ureteral stenosis (retroperitoneal fibrosis), two rare complications of Henoch-Schönlein purpura. The CT findings of hemorrhagic ureteritis are described.