Acute Epididymo-orchitis

Comments from Expert Advisory Committee

  1. Acute epididymo-orchitis is a clinical syndrome consisting of pain, swelling and inflammation of the epididymis +/- testes usually caused by local extension of infection from the urethra (sexually transmitted) or the bladder (urinary)
  2. Patients with epididymo-orchitis typically present with unilateral scrotal pain and swelling of relatively acute onset. There may be symptoms of urethritis or a UTI depending on the causative organism.
  3. Testicular torsion is the most important differential diagnosis. It is a surgical emergency. It should be considered in all patients, is more likely in younger patients and the onset of severe pain is usually short (i.e. within four hours).
  4. In men under 35 years it is more often a sexually transmitted infection (e.g. chlamydia, gonorrhoea or Mycoplasma genitalium). In men over 35 years, it is more often caused by a non-sexually transmitted gram-negative enteric pathogen causing urinary tract infection. A sexual history should be taken to determine risk of STIs. Mumps and TB can also cause epididymo-orchitis
  5. MSM who engage in insertive anal intercourse are at risk of epididymo-orchitis secondary to sexually transmitted enteric organisms
  6. All patients with urinary tract pathogen confirmed epididymo-orchitis should have further investigations of the urinary tract as anatomical or functional abnormalities are more common in this group.
  7. All patients presenting with symptoms and signs of epididymo-orchitis should have first void urine sent for chlamydia, gonorrhoea and Mycoplasma genitalium testing and a mid-stream urine sent for culture and sensitivity.
  8. All patients presenting with epididymo-orchitis should have a full STI screen (which includes a first void urine for chlamydia, gonorrhoea and Mycoplasma genitalium) and bloods for HIV, syphilis and Hepatitis B and C.
  9. Hepatitis C testing should be considered part of routine sexual health screening in the following circumstances: MSM, People living with HIV, Commercial sex workers, People who inject drugs (PWID). Partners of the above should also be considered for HCV testing.
  10. An ultrasound of the scrotum should be considered if there is uncertainty about the clinical diagnosis or need to exclude associated complications (hydrocoele, abscess, infarction)
  11. Individuals diagnosed with epididymo-orchitis should be advised to abstain from sexual intercourse until treatment completed and where indicated their partner has been treated. Where chlamydia or gonorrhoea are diagnosed, partner notification should be undertaken as per recommendations for those infections. All patients with a diagnosis of Mycoplasma genitalium should be referred to a GUM clinic.
  12. Where chlamydia or gonorrhoea have been diagnosed in patients with epididymo-orchitis, these infections are notifiable diseases. Notification process is usually initiated by the testing laboratory.


  • Rest, analgesia (paracetamol and/or ibuprofen if appropriate) and scrotal support are recommended.
  • Empirical antimicrobial therapy should be given to all patients with epididymo-orchitis before culture/NAAT results are available.
  • The antibiotic regimen chosen should be determined by age, sexual history, recent urinary tract instrumentation, other symptoms and where available initial test results (urethral smear, urinalysis, urine microscopy)
  • Follow-up is recommended within 3 days if symptoms don’t settle with empiric treatment
Drug Dose Duration +/- Notes
Likely to be sexually transmitted pathogen but NOT gonorrhoea

Doxycycline PO

100mg every 12 hours

10-14 days

Risk of photosensitivity.
Absorption significantly impaired by antacids, iron/calcium/magnesium/zinc containing products. Separate administration by 2-3hrs

Ofloxacin PO 200mg every 12 hours 14 days

See fluoroquinolone warning below

Likely to be sexually transmitted INCLUDING gonorrhoea

  • If allergic to cephalosporins, recommend onward referral to a dedicated STI clinic.
  • Gonorrhoea cultures must be sent prior to treatment.

Ceftriaxone IM


Doxycycline PO



100mg every 12 hours

Single dose


10-14 days

Ceftriaxone: Dissolve 1g ceftriaxone in 3.5ml of 1% Lidocaine Injection for IM injection. Not for IV injection

Risk of photosensitivity.
Absorption significantly impaired by antacids, iron/calcium/magnesium/zinc containing products. Separate administration by 2-3hrs

Likely to be enteric pathogen (urinary tract source or history of receptive anal intercourse)
Ofloxacin PO 200mg every 12 hours 14 days See Fluoroquinolone warning below.
Ciprofloxacin PO 500mg every 12 hours 10 days

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Reviewed December 2021