Acute scrotal swelling.

Acute scrotal swelling is a potential emergency. The differential diagnosis includes torsion of the testis or one of the testicular appendages, hydrocele, varicocele, trauma, tumor, idiopathic scrotal edema, and Henoch-Schönlein purpura. Imaging studies, such as radionuclide scanning and color Doppler ultrasonography, are helpful in equivocal cases.