Snapshot A 20-year-old man presents with left-sided testicular pain and swelling. He has a past medical history of multiple sexually transmitted infections. On physical exam, his left scrotum and testicle are erythematous, indurated, and tender to palpation. An ultrasound reveals a thickened epididymis. He is sent to the lab for testing for sexually transmitted diseases. Introduction Clinical definition inflammation of epididymis with symptoms of < 6 weeks Epidemiology incidence login to view 1 more bullet demographics login to view 1 more bullet risk factors login to view 2 more bullets Etiology pathogens from sexually transmitted infections in men less than 35 years of age login to view 2 more bullets urinary tract pathogens in men greater than 35 years of age login to view 1 more bullet Pathogenesis consequence of sexually transmitted disease or urinary tract infection login to view 1 more bullet bladder outlet obstruction login to view 1 more bullet Prognosis resolves with antibiotics Presentation Symptoms testicular pain and often unilateral lower abdominal pain urinary frequency or urgency urinary dysuria Physical exam fever testicular erythema, tenderness, and induration cremasteric reflex intact Prehn's sign login to view 1 more bullet Imaging Ultrasound indications login to view 1 more bullet findings login to view 3 more bullets Studies Urine positive leukocyte esterase 10 or more wbc/hpf nucleic amplification testing for Chlamydia and Neisseria Differential Testicular torsion absent cremasteric reflex Treatment Medical antibiotics guided by sexual and urologic history login to view 4 more bullets Complications Sepsis Testicular atrophy