Causes of a Warm, Swollen, and Tender Scrotum
A warm, swollen, and tender scrotum is most commonly caused by testicular torsion, epididymitis/epididymoorchitis, or torsion of testicular appendage, with testicular torsion representing a surgical emergency requiring immediate intervention within 6-8 hours to prevent testicular loss. 1, 2
Primary Causes and Clinical Presentation
Epididymitis/epididymoorchitis is the most common cause in adolescents and adults, characterized by gradual onset of pain, positive Prehn sign (pain relief when testicle is elevated), and increased blood flow on ultrasound 2
Testicular torsion presents with sudden-onset severe pain, negative Prehn sign, high-riding testicle, and absent cremasteric reflex, requiring surgical intervention within 6-8 hours to prevent permanent ischemic damage 2, 3
Torsion of testicular appendage is the most common cause in prepubertal boys, sometimes presenting with a "blue dot sign" (visible through skin in only 21% of cases) 1, 2
Less common causes include idiopathic scrotal edema, hydrocele, inflammation of tunica vaginalis, trauma, testicular tumors, epididymal cysts, Fournier gangrene, scrotal abscess, and strangulated inguinal hernia 1
Age-Related Considerations
Epididymitis/epididymoorchitis is most common in adolescent boys and adults, accounting for 1 in 44 outpatient visits in men 18-50 years 1
Testicular torsion has a bimodal distribution, occurring more frequently in neonates and postpubertal boys, with yearly incidence of 2.9-3.8 per 100,000 boys under 18 years 1, 3
Torsion of testicular appendage is the most common etiology in prepubertal boys 1, 2
Diagnostic Approach
Ultrasound with Doppler is the first-line imaging for acute scrotal pain, helping differentiate between various causes 2
For testicular torsion, key ultrasound findings include decreased or absent blood flow to the affected testicle and the "whirlpool sign" of the twisted spermatic cord 3
If history and physical examination strongly suggest testicular torsion, immediate surgical exploration is indicated without delay for imaging studies 4
MRI may be useful when ultrasound is inconclusive 2
Clinical Pearls and Pitfalls
Testicular torsion is a surgical emergency - delay beyond 6-8 hours significantly increases risk of permanent damage and need for orchiectomy 3, 4
The absence of cremasteric reflex is the most accurate physical examination sign of testicular torsion 5
Clinical presentations of the three most common causes can overlap, making accurate diagnosis challenging 2
Manual detorsion by external rotation of the testicle can be attempted while arranging for surgical intervention, but blood flow must be confirmed after the maneuver 5
Even with successful treatment of testicular torsion, exocrine function may remain abnormal, potentially affecting fertility 6