How should I differentiate between testicular torsion and epididymitis in a patient presenting with acute scrotal pain?

Differentiating between testicular torsion and epididymitis in a patient presenting with acute scrotal pain is critical due to the emergency nature of testicular torsion ¹.

Testicular Torsion:

• It is typically characterised by sudden-onset scrotal pain ¹.
• Testicular torsion is a urological emergency, and if clinically suspected, immediate surgical exploration is necessary ¹.
• If testicular torsion is suspected, the patient requires emergency hospital admission to urology or paediatric surgery ¹.
• Surgical repair should ideally be performed within 4 hours to salvage the testicle ¹.
• A history of previous episodes of severe, self-limiting scrotal pain or swelling may indicate spontaneous testicular torsion and detorsion, which warrants a urology referral ¹.

Epididymitis:

• If an adolescent or adult has suspected epididymo-orchitis, emergency hospital admission is arranged if symptoms are severe, the person is systemically unwell, or there is a suspected serious complication ¹.
• Serious complications that may require urgent ultrasound and/or hospital admission include testicular abscess or infarction ¹.
• If hospital admission is not needed, management involves identifying the most likely causative organism based on the person's age, urine dipstick results, and risk factors ¹.
• This may involve assessing the risk of a sexually transmitted infection (STI) or an enteric organism associated with a lower urinary tract infection (UTI) ¹.
• If an STI is the most likely cause, urgent referral to a local specialist sexual health clinic is advised for testing, treatment, and possible contact tracing ¹.
• If an enteric organism is the most likely cause, a urine dipstick test and mid-stream urine (MSU) sample for microscopy and culture should be arranged, and empirical antibiotic treatment may be considered ¹.