Acute Scrotal Swelling Evaluation and Management

Introduction to Acute Causes

The American Urological Association recommends immediate evaluation of scrotal swelling to exclude testicular torsion, a surgical emergency requiring intervention within 6-8 hours to prevent testicular loss 1
Testicular torsion presents with abrupt onset of severe unilateral scrotal pain and swelling, often accompanied by nausea and vomiting, and is more common in adolescents with a bimodal distribution, but can occur at any age 1, 2
The European Association of Urology suggests that pain not relieved by elevating the testis (negative Prehn sign) distinguishes testicular torsion from epididymitis 1

The American College of Emergency Physicians recommends immediate clinical assessment focusing on onset, pain severity, and Prehn sign for any acute scrotal swelling 1
If there is high suspicion for torsion, proceed directly to surgical exploration without imaging, and if intermediate suspicion, perform urgent Duplex Doppler ultrasound with grayscale, color Doppler, and power Doppler 1
Compare the affected testis to the contralateral side as an internal control, as asymmetry in blood flow is key, and remember that there is a 30% false-negative rate for Doppler in partial torsion 1

The European Urology Association recommends urgent surgical debridement and broad-spectrum antibiotics for Fournier's gangrene, which presents with severe pain, rapidly progressive scrotal swelling, skin necrosis, and systemic toxicity 3
The American Urological Association suggests that epididymitis, the most common cause of scrotal pain and swelling in adults, should be treated with ceftriaxone 1000 mg IV/IM plus doxycycline for sexually transmitted infections, and fluoroquinolones or cephalosporins for enteric organisms in older men 3
The World Health Organization recommends combination drug therapy for genitourinary tuberculosis, including 2 months of isoniazid, rifampicin, pyrazinamide, and ethambutol, followed by 4 months of isoniazid and rifampicin 3

Torsion of the testicular appendage is the most common cause of testicular pain in prepubertal boys, and ultrasound shows normal testicular perfusion with localized hyperemia near the appendage 1
Acute idiopathic scrotal edema is a rare, self-limiting condition with marked scrotal wall thickening but minimal pain, and diagnosis is made by exclusion, showing increased peritesticular blood flow but normal testicular vascularity 1