Epididymo-orchitis is a clinical syndrome consisting of pain, swelling and inflammation of the epididymii and testes. It occurs most commonly as a complication of a urethral infection caused by sexually transmitted pathogens (Chlamydia trachomatis, Neisseria gonorrhoea) in sexually active men, or a urinary tract infection caused by enteric Gram-negative bacteria (Pseudomonas, Klebsiella or Proteus  spp, E. Coli) in non-sexually active men (eg prepubertal boys, older men). It can also occur secondary to a number of systemic bacterial infections (extrapulmonary tuberculosis, syphilis,) and viral infections (mumps). Men who engage in insertive anal sex are at risk of infection with sexually acquired enteric pathogens in addition to other sexually transmitted pathogens.

Differential diagnosis

Differential diagnosis includes:

  • Testicular torsion
  • Torsion of epididymal appendage
  • Trauma
  • Hydrocoele
  • Epididymal cyst
  • Testicular tumour

Testicular torsion is a surgical emergency which should be considered in all patients and excluded first. It most commonly occurs in males aged <20 but can occur at any age. If testicular torsion is suspected, the patient should be referred for URGENT urological assessment including ultrasound scan with Doppler.

Diagnosis of epididymo-orchitis 


  • Unilateral scrotal pain and swelling of relatively acute onset. 
  • There may be symptoms of urethritis or urinary tract infection but patients may be asymptomatic
  • Signs on examination: swollen testis or epididymis, with tenderness to palpation on the affected side.
  • Urethral discharge may or may not be present.
  • Fever

Urethral swab for Gram stain if discharge is present
Urethral swab or first void urine tests for chlamydia, gonorrhoea and Mycoplasma genitalium
MSU for microscopy, culture and sensitivities
If clinically suspected consider tests for mumps virus and tuberculosis.


Pain relief, rest and scrotal support 

Antibiotics should aim to cover the most likely causes.

Where a sexually transmitted pathogen is the most likely cause:

Azithromycin 1 g single dose PLUS doxycycline 100 mg twice daily for 14 days

In addition, if gonorrhoea is suspected or possible ADD: Ceftriaxone 500 mg stat IMI

If an enteric organism is suspected:

Ciprofloxacin 500mg twice daily for 10 days (Ceftriaxone 500 mg IMI may be added for men who are at risk of both enteric and sexually transmitted pathogens, e.g. MSM who report insertive anal intercourse)

Review at 48 hours and if there is no improvement the diagnosis should be re-evaluated or admission considered.

If symptoms of sepsis or systemic symptoms are present admission to hospital for rest and intravenous antibiotic treatment should be considered.

Partner treatment

All partners of men with epididymo-orchitis not secondary to an enteric pathogen should be tested and managed accordingly.

The content of these treatment guidelines is for information purposes only. The treatment guidelines are generic in character and should be applied to individuals only as deemed appropriate by the treating practitioner on a case by case basis. Alfred Health, through MSHC, does not accept liability to any person for the information or advice (or the use of such information or advice) which is provided through these treatment guidelines. The information contained within these treatment guidelines is provided on the basis that all persons accessing the treatment guidelines undertake responsibility for assessing the relevance and accuracy of the content and its suitability for a particular patient. Responsible use of these guidelines requires that the prescriber is familiar with contraindications and precautions relevant to the various pharmaceutical agents recommended herein.

Last Updated December 2014