Acute Scrotal Pain & Testicular Torsion

Approach to acute scrotal pain

Broad causes: infective (epididymo-orchitis), structural (testicular torsion, torsion of the testicular appendage, hernia), and pathological (testicular cancer — often painless until necrosis occurs). Always exclude testicular torsion first in any acute scrotal pain presentation, regardless of how likely another cause seems.

Testicular torsion

Definition: rotation of the testicle along the longitudinal axis of the spermatic cord, cutting off its blood supply. The degree of rotation (typically 90–180°) and duration of ischaemia determine salvage rates — viability drops sharply after ~6 hours, though salvage has occasionally been reported even at 24–48 hours. Always refer emergently to the ED for urgent surgical review — do not wait to see if pain settles.

Epidemiology: can occur at any age but is much less common in older men; bimodal peaks in neonates and adolescents (65% of cases occur aged 12–18).

Presentation

• Acute onset of pain within minutes, escalating quickly to a constant severe ache or sharp stabbing pain in the scrotum and groin.
• Swelling, nausea and vomiting often accompany the pain.
• A history of vigorous physical activity or minor testicular trauma can precede torsion.
• Abdominal pain is common alongside the scrotal pain — a useful pointer away from epididymo-orchitis.
• Intermittent (self-resolving) torsion may present as a history of waking at night with pain.

Examination

• An asymmetric, high-riding testis with a horizontal lie (from the shortened spermatic cord) is the classic finding, present in about half of cases — its absence does not rule out torsion.
• Prehn’s sign (pain relief with scrotal elevation): a negative Prehn’s sign makes torsion more likely, but a positive Prehn’s sign does not exclude torsion.
• Cremasteric reflex may be absent in torsion, but this is not a reliable discriminator.

Investigations

Doppler ultrasound of both testes is 86–100% sensitive and 95–100% specific, but is highly operator-dependent. A normal ultrasound does not rule out torsion if the history and examination point strongly toward it — proceed to surgical exploration regardless.

Management

Immediate surgical exploration with detorsion (or orchidectomy if non-viable) and prophylactic fixation of both testes to prevent future events. Non-viability rates reach ~75% by 12 hours post-torsion, but surgery should still not be withheld purely because of symptom duration beyond 6 hours — salvage has been reported even very late.

Differentiating the three classic causes of acute scrotal pain

	Testicular torsion	Epididymitis	Torsion of the appendix testis
Onset	Sudden	Insidious	Gradual
Associated symptoms	Severe pain, nausea/vomiting, possible trauma, possible abdominal pain	Fevers/rigors, LUTS, relevant sexual history	Moderate-severe pain, nausea/vomiting
Signs	Asymmetric high-riding testis, negative Prehn’s sign, absent cremasteric reflex	Indurated testis, tender upper pole, positive Prehn’s sign, intact cremasteric reflex	Localised anterior tenderness, ‘blue dot’ sign

Torsion of the appendix testis is the most common cause of scrotal pain in children and can mimic true torsion closely (severe acute pain, nausea/vomiting) — the more gradual onset is the main clinical clue. Examination often shows a hydrocoele and localised anterior tenderness; the “blue dot” sign (a visible infarcted appendage) is sometimes seen. Ultrasound may show a hypoechogenic focus with normal/increased testicular blood flow. Management is conservative (NSAIDs, rest, ice, scrotal support/elevation) — pain can last several weeks. Surgery is reserved for worsening or severe pain unresponsive to conservative measures, or to relieve parental anxiety; routine surgical exploration remains debated and isn’t well supported by evidence, especially in adults.