Reasoning GP · Algorithm · 1-page summary
Acute and chronic scrotal pain
For: adults and young people with acute or chronic (≥3 months) scrotal pain. Not for: a painless lump or swelling (use Scrotal Lumps and Swelling). Children: local paediatric surgical pathway.
Core rule: sudden-onset or severe unilateral scrotal pain is torsion until proven otherwise, at any age. No single sign, no normal Doppler and no response to analgesia excludes it — transfer, do not scan.
0Stop — emergency transfer now — before any test
- Possible torsion: sudden severe unilateral pain, high or horizontal testis, nausea or vomiting, absent or uncertain cremasteric reflex, or torsion not confidently excluded → Emergency transfer to a service able to operate; 999 if unstable or unsafe to transfer.
- Fournier's gangrene (severe pain, systemic illness, skin necrosis, bullae, crepitus, rapidly spreading swelling) or sepsis / haemodynamic instability → 999
- Trauma with expanding haematoma, haematocele or suspected rupture; irreducible inguinoscrotal hernia (vomiting, abdominal pain) → Emergency transfer
- While arranging: analgesia now; do not wait for ultrasound, tests or response to analgesia. Surgery is still worthwhile after 6 hours. Children → a centre able to explore, not just for an ultrasound.
1Triage by presentation — which pathway?
| Presentation | Route |
|---|---|
| Sudden / severe | Torsion until excluded → block 0, any age |
| Brief episodes, resolved | Possible intermittent torsion → Urgent urology |
| Gradual, hours–days | Epididymo-orchitis likely → test, then treat by risk (block 5) |
| ≥3 months | Exclude structural, malignant, infective, referred causes → chronic pathway |
2Screen — one row is enough
- Vomiting or pain preventing oral treatment, suspected abscess or infarction, immunocompromise with significant infection → Same-day hospital
- Epididymo-orchitis not improving at 48–72 h → Same-day hospital; reconsider torsion, abscess or the wrong organism.
- Non-painful enlargement or change in shape or texture of the testis → consider Suspected cancer pathway (NG12). Solid intratesticular lesion on USS → refer on it.
- Unexplained or persistent testicular symptoms, persistent swelling or poor response → consider Urgent direct-access USS (NG12).
3Assess — only once block 0 is excluded
☐ Temperature, HR, BP, RR, SpO₂, sepsis check ☐ Chaperone offered; examine standing and supine: lie, epididymis, cord, skin, hernias, abdomen, loins ☐ Dipstick and MSU ☐ First-pass urine NAAT before antibiotics, if no delay ☐ HIV and syphilis tests if STI suspected
Not in primary care: ordering or awaiting USS when torsion is suspected; Prehn's sign; tumour markers that delay referral; PSA during active infection.
4Classify — only if block 0 is excluded
- Appendage torsion — upper-pole tenderness ± blue dot; only if confident: analgesia, safety-net.
- Epididymo-orchitis — gradual onset, tender epididymis, ± fever, urinary or urethral symptoms. Pathogen from sexual and urinary risk, not age alone.
- Referred — scrotum often normal: renal colic, hernia, groin nerve, lumbar spine, hip.
- Structural — hydrocele or cyst transilluminates; varicocele right-sided or non-reducing → imaging.
- Uncertain — torsion not confidently excluded → Emergency transfer.
5Treat today — doses: NICE, SPC and local formulary
- Likely sexually acquired: ceftriaxone 1 g IM once + doxycycline 100 mg BD 10–14 days (BASHH) via sexual health; no sex until treated, improved and partners treated.
- Likely enteric: MSU first; BASHH/local guidance (ofloxacin 200 mg BD 14 days); fluoroquinolone only if other antibiotics are inappropriate (MHRA). Mixed risk → discuss with sexual health or microbiology.
- Analgesia for all, never delaying transfer: paracetamol, NSAID if no contraindication, scrotal support.
- Chronic pain: explain; activity, psychological therapy, pelvic-floor physio; no prolonged antibiotics without infection.
6Refer routinely
- Sexual health: positive NAAT, partner notification, M. genitalium, gonorrhoea test of cure where indicated.
- Urology: varicocele if symptomatic, right-sided, bilateral, large or with subfertility; large symptomatic hydrocele; chronic pain persistent, disabling or post-vasectomy (or pain service). Uropathogen with recurrent infection or tract abnormality → Urgent
7Never reassure by
- A normal Doppler ultrasound, or waiting for one.
- Pain easing with analgesia.
- A present cremasteric reflex, a normal testicular lie or Prehn's sign.
- Age — torsion occurs at any age; age alone does not set the pathogen.
- Known chronic pain when new acute severe pain appears.
- Persisting "infection" — a tumour can hide behind it.
8Safety-net — say it, then document it
999 “Any new sudden or severe testicular pain — even if you have had pain there before — or scrotal skin turning dark, blistering or crackly with feeling very unwell: call 999 or go to A&E now.” Same day: “Fever not settling after 48–72 hours of antibiotics, swelling getting worse, feeling more unwell or unable to keep the tablets down — contact us today. On ofloxacin, stop and get advice if you get tendon pain, tingling, mood change or confusion.”
Follow-up: review at 48–72 h with MSU and NAAT results, then at 1–2 weeks. A new painless change in the testis → back promptly, whatever a previous scan showed.
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies; torsion confidently excluded
Observations normal; chaperone offer recorded
Dipstick, MSU and NAAT sent before antibiotics
Regimen matched to risk; sexual-health and partner plan
48–72 h review booked; safety-net given
Summary of the full Reasoning GP scrotal pain algorithm, which holds the detail, examination, investigations, chronic-pain management and evidence. Sources: BASHH epididymo-orchitis (2020) and gonorrhoea (2025); NICE NG12 (updated April 2026), NG193, CG173; GIRFT/BAUS testicular torsion pathway; IUSTI 2024; EAU chronic pelvic pain; local antimicrobial guidelines; MHRA (January 2024). Clinical reference — follow the local emergency urology pathway and check doses: NICE, SPC and local formulary.