Red flags
- Testicular torsion must be excluded first and urgently in any acute scrotal pain presentation - testicular viability falls sharply beyond 6 hours from onset, making this a true surgical emergency where diagnostic delay directly costs testicular salvage
- Fournier gangrene (necrotising fasciitis of the perineum/scrotum) - rapidly progressive, systemically unwell, disproportionate pain
Differential by mechanism
Testicular torsion (peak in adolescents but possible at any age, sudden severe onset)
Epididymo-orchitis (STI-related in younger sexually active men, urinary pathogen-related in older men/recent instrumentation)
Torsion of testicular appendage (a benign mimic of torsion, often with a more localised "blue dot" sign)
Testicular trauma, incarcerated inguinal hernia, testicular tumour (usually painless but can present with acute pain from haemorrhage/infarction into a tumour)
Focused history
- Onset speed and severity (sudden, severe favours torsion; more gradual onset over hours-days favours epididymo-orchitis), associated urinary symptoms (dysuria, discharge suggesting infective cause), sexual history and STI risk factors, trauma history, prior similar episodes (intermittent torsion-detorsion history)
- Nausea/vomiting is common with torsion given the visceral pain response
Focused examination
- Testicular position/lie (a high-riding, horizontally-oriented testis suggests torsion), cremasteric reflex (classically absent in torsion, though an unreliable sole discriminator), tenderness distribution (diffuse testicular tenderness favours torsion, epididymal-predominant tenderness favours epididymo-orchitis), scrotal skin changes (erythema/oedema can occur with either but marked systemic toxicity raises Fournier gangrene concern)
- Absence of the cremasteric reflex alone is not reliably diagnostic and should not be used to exclude or confirm torsion without further assessment
Investigation strategy
- Urgent scrotal Doppler ultrasound (absent/reduced testicular blood flow supports torsion) - but imaging should never delay urgent urological referral when clinical suspicion for torsion is high, given the time-critical nature of surgical exploration/detorsion
- Urine NAAT for chlamydia/gonorrhoea and midstream urine culture once torsion is excluded, to guide organism-directed antibiotic therapy for epididymo-orchitis
Management
- Suspected torsion: immediate urological referral for surgical exploration - do not wait for ultrasound confirmation if clinical suspicion is high and imaging would meaningfully delay theatre
- Confirmed epididymo-orchitis: empirical antibiotics matched to likely organism by age/risk factors (STI-directed cover in younger sexually active men, urinary pathogen cover in older men), with partner notification/STI screening if an STI organism is identified or suspected
Traps
Waiting for ultrasound before urological referral when clinical suspicion for torsion is high - this delay directly costs testicular salvage time
Relying on cremasteric reflex alone to exclude torsion - an unreliable single discriminator
Assuming epididymo-orchitis in a young man without excluding torsion first - the two can present similarly early in the course
Talk track
"Testicular pain that comes on suddenly can be caused by the testicle twisting on itself, which is an emergency needing surgery straight away - because of this, I'm going to arrange urgent assessment by the urology/surgical team now, and we may do this before waiting for a scan if it would delay getting you to theatre."
8 of 8 sections written · drafted 2026-09-14