Acute scrotum — torsion vs epididymo-orchitis

Clinical discrimination. Torsion: sudden severe pain, nausea/vomiting, high horizontal testis, absent cremasteric reflex, short ischaemic history. Epididymo-orchitis: more gradual onset, urinary symptoms/STI risk, fever, often preserved cremasteric, Prehn may relieve pain (unreliable). Appendix testis torsion may show a blue-dot sign with preserved testicular flow.^[6]

TWIST formalises pre-test risk (hard testis, absent cremasteric, nausea/vomiting, high-riding, swelling). High scores go straight to theatre; low scores may use Doppler; intermediate scores need imaging if not exploring immediately.^[6][8]

Imaging policy. Colour Doppler is useful when the diagnosis is uncertain; it must not delay exploration when clinical suspicion is high, and a normal ultrasound never fully excludes torsion. A normal urinalysis does not exclude torsion.^[8]

Management. Urgent exploration is definitive. Manual detorsion (medial-to-lateral “open book”) can buy time but does not replace surgery. Bilateral orchiopexy because the deformity may be bilateral; orchidectomy if non-viable.^[4]