Epididymo-orchitis
Gradual painful swelling behind the testis with urine symptoms. But torsion is a clinical diagnosis: sudden severe pain in a young man means surgery now.
A 24-year-old man has had a painful, swollen right testis for 3 days with burning when passing urine and a temperature of 37.9 °C. He has a new sexual partner.
A 68-year-old man with a long-term catheter has a hot, red, swollen left scrotum and is feverish.
A 14-year-old boy says his left testis started hurting suddenly 3 hours ago.
Which one can't wait for an ultrasound, and which antibiotics do the other two need?
- Sudden severe testicular pain in a young personTorsion until proven otherwise: urgent urology, theatre within 6 hours. Don't wait for ultrasound.
- HistoryOnset, urinary symptoms, sexual history, catheter, mumps.
- ExamineTestis lie, epididymal tenderness, cremasteric reflex, hernia, abscess.
- TestsUrine dipstick and culture, first-pass urine NAAT for chlamydia and gonorrhoea, urethral swab if discharge.
- Sexually acquired likelyCeftriaxone plus doxycycline.
- Enteric organisms likelyOfloxacin or ciprofloxacin.
- SupportiveRest, scrotal support, analgesia. Partner notification for STIs.
- Possible torsion
- Abscess or fluctuant scrotum
- Sepsis
- No improvement in 3 days
- Gangrene or crepitus (Fournier's)
- Testicular torsion
- Testicular tumour
- Fournier's gangrene
- Torsion of the appendix testis
- Inguinal hernia
- TB epididymitis
| Torsion window | Best salvage within 6 hours |
| STI cover | Ceftriaxone 500 mg–1 g IM once plus doxycycline 100 mg twice daily for 10–14 days |
| Enteric cover | Ofloxacin 200 mg twice daily for 14 days or ciprofloxacin 500 mg twice daily for 10 days |
| Under 35 or new partner | Usually sexually acquired |
| Over 35, catheter, or recent procedure | Usually enteric organisms |
Check every dose against a current drug reference and your hospital protocol.
On this page
Causes
| Group | Organisms | Clues |
|---|---|---|
| Sexually acquired | Chlamydia, gonorrhoea, Mycoplasma genitalium | Younger, new partner, urethral discharge |
| Enteric | E. coli and others | Older, prostate enlargement, catheters, recent procedures |
| Mumps | Mumps virus | Parotid swelling a few days before; often in teenagers and young adults |
| TB | Mycobacterium tuberculosis | Chronic, hard, beaded vas, sinus |
| Drugs | Amiodarone | Non-infective |
Torsion or epididymo-orchitis?
Torsion: urology now
Epididymo-orchitis
Torsion of the appendix testis
Prehn's sign (pain relief on lifting the testis) is not reliable enough to exclude torsion.
Investigations
| Test | Why |
|---|---|
| Urine dipstick and culture | Enteric infection |
| First-pass urine NAAT | Chlamydia and gonorrhoea |
| Urethral swab and Gram stain | Gonorrhoea if discharge |
| Ultrasound with Doppler | Abscess, tumour, uncertain diagnosis (not to delay torsion surgery) |
| HIV, syphilis serology | If sexually acquired |
| Mumps IgM or PCR | Suspected mumps |
| Early morning urine for AFB | Chronic or TB suspected |
Treatment
Follow-up
- Review at 3 days; if not improving, ultrasound for abscess or tumour.
- Swelling and tenderness may take weeks to settle completely.
- STI: partner notification and testing, no sex until both treated.
- Persistent lump after treatment: ultrasound to exclude tumour.
Common mistakes
- Diagnosing epididymitis in a teenager with sudden pain (torsion).
- Waiting for ultrasound before theatre in suspected torsion.
- Treating with an enteric antibiotic only in a young sexually active man.
- Forgetting partner notification.
- Missing a tumour presenting as "epididymitis that won't settle".
Frequently asked questions
How do you tell epididymo-orchitis from testicular torsion?
Torsion starts suddenly and severely, often in boys and young men, with a high-riding testis and absent cremasteric reflex. Epididymo-orchitis develops over days with urinary symptoms and fever. If in doubt, treat as torsion.
What causes epididymo-orchitis in young men?
Usually sexually transmitted infections such as chlamydia and gonorrhoea.
What is the treatment for sexually acquired epididymo-orchitis?
Ceftriaxone as a single IM dose plus doxycycline for 10–14 days.
What causes epididymo-orchitis in older men?
Usually enteric organisms such as E. coli, linked to prostate enlargement, catheters and urinary procedures.
Test yourself
Exam-style questions on this guide, from our two question banks. Choose an answer to see why each option is right or wrong.
1. A 32-year-old has 3 days of gradually increasing testicular pain, fever and dysuria; cremasteric reflex present. What is likely?
Answer: Epididymo-orchitis. Gradual onset with urinary symptoms suggests infection.
- Testicular tumour: Painless.
- Varicocele: No.
- Hydrocele: Painless.
- Testicular torsion: Sudden onset, absent reflex.
2. Which regimen suits epididymo-orchitis in a sexually active 25-year-old?
Answer: Ceftriaxone, doxycycline. Covers gonorrhoea and chlamydia.
- Amoxicillin: No.
- No antibiotics: No.
- Metronidazole: No.
- Ofloxacin alone: Enteric cover, not gonorrhoea.
3. A man has a painless, craggy epididymal swelling and beaded vas deferens. What should be considered?
Answer: Tuberculous epididymitis. Test for TB.
- Torsion: Painful, sudden.
- Spermatocele: Smooth.
- Acute bacterial epididymitis: Painful.
- Mumps: Painful.
4. A 25-year-old sexually active man has 3 days of gradually increasing scrotal pain, swelling, dysuria and fever. Elevating the testis relieves pain. What is the treatment?
Answer: Ceftriaxone + doxycycline. Epididymo-orchitis: young sexually active men → Chlamydia/gonorrhoea → ceftriaxone single dose + doxycycline 10–14 days (treat partners). Older men/UTI-related → enteric organisms → quinolone. Mumps orchitis in unvaccinated. Gradual onset, dysuria, fever, Prehn sign positive (elevation relieves pain). If any doubt about torsion → explore.
- Immediate exploration: Exploration is not needed with a positive Prehn sign and gradual onset.
- Nitrofurantoin: Nitrofurantoin does not cover STIs.
- No treatment: Infection needs treatment.
5. A 24-year-old sexually active man has 3 days of gradually increasing right testicular pain and swelling, with dysuria and urethral discharge. The epididymis is tender; the testis lies normally and the cremasteric reflex is present. What is the treatment?
Answer: Ceftriaxone + doxycycline. Gradual onset, urethral symptoms, a tender epididymis and a preserved cremasteric reflex suggest epididymo-orchitis. In men under 35 it is usually sexually transmitted (Chlamydia, gonorrhoea): treat with ceftriaxone plus doxycycline, test for STIs and notify partners. In older men, enteric organisms are more likely (quinolone). If torsion cannot be excluded, explore.
- Emergency scrotal exploration: Only if torsion can’t be excluded.
- Oral nitrofurantoin: Poor tissue levels; misses STIs.
- Ciprofloxacin alone: Doesn’t reliably cover gonorrhoea (resistance).
6. Which nerve runs through the inguinal canal but outside the spermatic cord?
Answer: Ilioinguinal nerve. The ilioinguinal nerve enters the inguinal canal from the side (not through the deep ring) and lies on the cord, outside its fascial coverings, before leaving through the superficial ring to supply the upper medial thigh and anterior scrotum. It can be injured in hernia repair. The genital branch of the genitofemoral nerve is inside the cord.
- Genital branch of genitofemoral nerve: Inside the cord; supplies cremaster.
- Vas deferens nerve plexus: Not the answer.
- Testicular sympathetic plexus: Inside the cord with the testicular artery.
- Pudendal nerve: Not in the inguinal canal.
7. The internal spermatic fascia of the spermatic cord is derived from which layer?
Answer: Transversalis fascia. As the testis descends through the abdominal wall, it picks up a covering from each layer. The internal spermatic fascia comes from the transversalis fascia at the deep inguinal ring. The cremasteric muscle and fascia come from the internal oblique (and transversus) at the canal, and the external spermatic fascia comes from the external oblique at the superficial ring. The processus vaginalis of peritoneum becomes the tunica vaginalis. Transversus abdominis contributes no separate covering because it arches above the deep ring.
- External oblique aponeurosis: This forms the external spermatic fascia.
- Internal oblique muscle: This forms the cremaster.
- Transversus abdominis aponeurosis: Transversus contributes no separate layer.
- Parietal peritoneum: Peritoneum forms the tunica vaginalis.
References and dose sources
- BASHH — Epididymo-orchitis guideline (2020)
- NICE CKS — Scrotal pain and swelling
- Ceftriaxone dosing: Drugs.com: Ceftriaxone dosage (see also our ceftriaxone dose page)
- Doxycycline dosing: Drugs.com: Doxycycline dosage (see also our doxycycline dose page)
- Ofloxacin dosing: Drugs.com: Ofloxacin dosage (see also our ofloxacin dose page)
- Ciprofloxacin dosing: Drugs.com: Ciprofloxacin dosage (see also our ciprofloxacin dose page)
- Ibuprofen dosing: Drugs.com: Ibuprofen dosage (see also our ibuprofen dose page)
International guidance is linked where it reflects good practice. Where your hospital’s protocol differs, follow your hospital.