 Introduction/Background The acute scrotum is a medical emergency defined as scrotal pain, swelling and redness of acute onset, from minutes to 1 to 2 days [1] and comprises at least 0.5% of all emergency department visits [2]. Etiologies of acute scrotum are numerous, and rapid accurate diagnosis is essential to appropriately triage potentially surgical and irreversible conditions from patients for whom conservative management is sufficient. Diagnostic considerations include testicular torsion, torsion of testicular appendage, epididymoorchitis, epididymitis, idiopathic scrotal edema, hydrocele, inflammation of the tunica vaginalis, trauma, testicular tumors, epididymal cysts, Fournier gangrene, scrotal abscess, and strangulated inguinal hernia [3-6]. Torsion of a testicular appendage, epididymitis, and testicular torsion are the three most common causes of acute scrotal pain and account for approximately 85% to 90% of cases [7]. Large differential diagnoses and overlapping clinical presentation make the acute scrotum a diagnostic challenge. Acute epididymoorchitis or epididymitis is the most common cause of acute scrotum in adolescent boys and adults [8,9]. In 2002, epididymitis or epididymoorchitis accounted for 1 in 44 outpatient visits in men 18 to 50 years of age [9,10]. Although uncommon in pediatric populations, it can be associated with urinary tract infections and/or structural and functional abnormalities of the urinary tract [11,12]. Epididymitis has a more insidious and gradual onset than testicular torsion. As inflammation and edema progress, a reactive hydrocele may develop making it difficult to differentiate from testicular torsion. Clinically, scrotal pain associated with epididymitis is usually relieved when the testes are elevated over the symphysis pubis (the Prehn sign) [8,13].
Acute Onset of Scrotal Pain Without Trauma Without Antecedent Mass.  Introduction/Background The acute scrotum is a medical emergency defined as scrotal pain, swelling and redness of acute onset, from minutes to 1 to 2 days [1] and comprises at least 0.5% of all emergency department visits [2]. Etiologies of acute scrotum are numerous, and rapid accurate diagnosis is essential to appropriately triage potentially surgical and irreversible conditions from patients for whom conservative management is sufficient. Diagnostic considerations include testicular torsion, torsion of testicular appendage, epididymoorchitis, epididymitis, idiopathic scrotal edema, hydrocele, inflammation of the tunica vaginalis, trauma, testicular tumors, epididymal cysts, Fournier gangrene, scrotal abscess, and strangulated inguinal hernia [3-6]. Torsion of a testicular appendage, epididymitis, and testicular torsion are the three most common causes of acute scrotal pain and account for approximately 85% to 90% of cases [7]. Large differential diagnoses and overlapping clinical presentation make the acute scrotum a diagnostic challenge. Acute epididymoorchitis or epididymitis is the most common cause of acute scrotum in adolescent boys and adults [8,9]. In 2002, epididymitis or epididymoorchitis accounted for 1 in 44 outpatient visits in men 18 to 50 years of age [9,10]. Although uncommon in pediatric populations, it can be associated with urinary tract infections and/or structural and functional abnormalities of the urinary tract [11,12]. Epididymitis has a more insidious and gradual onset than testicular torsion. As inflammation and edema progress, a reactive hydrocele may develop making it difficult to differentiate from testicular torsion. Clinically, scrotal pain associated with epididymitis is usually relieved when the testes are elevated over the symphysis pubis (the Prehn sign) [8,13].