Back to top


Epididymo-orchitis is the inflammation of the epididymis +/- the testis. This may be a result a bacterial infection with sexually transmitted pathogens or non-sexually transmitted uropathogens from the urinary tract. The most common cause in sexually active men is N. Gonorrhoeae and C.Trachomatis, particularly those


  • Sexually-transmitted
    • C.Trachomatis and N.Gonorrhoea
    • Men engaging in insertive anal intercourse are prone to infection by gram-negative enteric organisms such as E.coli and Proteus spp.
  • Non-sexually transmitted
    • Uropathogens - enteric gram-negative organisms
    • Increased risk if recent instrumentation of renal tract, outflow obstruction.

Other less common causes include Mumps, renal TB, Brucellosis, Candida, Amiodarone-induced, Behcet’s disease.

Clinical presentation

  • Acute onset of pain and swelling to testis

  • Urinary symptoms of dysuria, frequency and haematuria

  • Symptoms of urethritis such as, urethral discharge and penile irritation

  • Most important differential diagnosis is testicular torsion. This may be time critical, seek urgent surgical / urological review on appropriate investigation / management.

Clinical Examination

Typically there will be unilateral swelling, with tenderness along the testes posteriorly along the epididymis and potentially spreading to the whole of the testes. A hydrocele may develop and there may be redness to the hemi-scrotum with increased warmth.

Urethral discharge may also be noted.


  • Mid-stream urine specimen for microscopy and culture for those with non-STI aetiology

  • First pass urine specimen for those with suspected STI aetiology

    • For Nucleic Acid Amplification Test (NAAT) for N. Gonorrhoea and C. Trachomatis

  • Urethral swab for N. Gonorrhoea culture if urethral discharge present

  • Ultrasound may aid in differentiating epididymo-orchitis from testicular torsion in unclear cases. Ultrasound was found to be 86.1% sensitive and 85.7% specific for epididymo-orchitis (Agrawal, 2014). 

If patient has sexually acquired epididymo-orchitis, they should be screened for other sexually transmitted diseases such as blood borne virus; HIV, Hepatitis B and C.


For Sexually Transmitted


  • Ceftriaxone 500mg IM stat + Azithromycin 1g PO stat + Doxycycline 100mg PO BD for 14 days.

Age >35yo OR MSM*:

  • Add cephalexin 500mg PO tds-qid or norfloxacin 400mg PO BD for 14 days.

*MSM – men who have sex with men.

For Non-Sexually Transmitted

  • Trimethoprim 300mg orally 7 days; OR
  • Cephalexin 500mg orally BD 7 days; OR
  • Amoxycillin+clavulinic acid 500+125mg orally BD 7 days.

Reference: Therapeutic Guidelines

Admit if severe for parenteral treatment.

Adjunctive/Supportive therapy;

  • Ice packs
  • Scrotal Support
  • Anti-inflammatories
  • Sitz baths
  • Sexual abstinence for those with sexual-acquired infections


  • Hydrocele
  • Abscess
  • Infarction of testes
  • Infertility

Notification and Contact Tracing

If sexually acquired epididymo–orchitis (suspected or confirmed), all sexual partners from the past 6 months should be notified and evaluated.

Both Gonorrhoea and Chlamydia are notifiable diseases according to the Public Health Act 2010.

For more information on notification and contact tracing click here.

Further References and Resources

© Agency for Clinical Innovation 2023