Acute Epididymo-orchitis

Comments from Expert Advisory Group

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 epididymo-orchitis is more often caused by 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. Gay, bisexual and other men-who-have-sex-with-men (gbMSM) who engage in insertive anal intercourse are at risk of epididymo-orchitis secondary to sexually transmitted enteric organisms.
6. Further investigation of acute epididymo-orchitis is advisable in all cases where sexual transmission of infection has been ruled out as anatomical or functional abnormalities are more common in this group.
   
7. All patients presenting with signs and symptoms of epididymo-orchitis should have a mid-stream urine sent for culture and sensitivity and should be offered a full STI screen (which includes a first void urine for chlamydia, gonorrhoea and Mycoplasma genitalium), chlamydia and gonorrhoea testing from other anatomical sites in line with sexual history and bloods for HIV, syphilis and hepatitis B. Mycoplasma genitalium positive cases should be referred to GU / ID service for treatment and follow up.
   
8. Hepatitis C testing should be considered part of routine sexual health screening in the following circumstances: gbMSM, People living with HIV, Commercial sex workers, People who inject drugs (PWID). Partners of the above should also be considered for HCV testing.
9. Individuals diagnosed with epididymo-orchitis should be advised to abstain from sexual intercourse until treatment completed and where indicated their partner has been treated.
10. Where chlamydia or gonorrhoea are diagnosed, partner notification should be undertaken as per recommendations for those infections (see ‘Window period, Lookback period and Partner notification’ on the ‘Approach to an STI Consultation in Primary Care’ page). All patients with a diagnosis of Mycoplasma genitalium should be referred to a GUM clinic.
11. 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.

Treatment

• 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.

Useful resources

• National guidelines for the prevention and control of gonorrhoea and for minimising the impact of antimicrobial resistance in Neisseria gonorrhoeae
• Guidance on Mycoplasma genitalium testing and management in Ireland July 2024

Patient information

• Patient information on STIs and genital conditions is available at the HSE Sexual Health and Crisis Pregnancy website

Safe Prescribing

Visit the safe prescribing page

• Doses are oral and for adults unless otherwise stated
• Dosing in children quick reference dosage/weight guide
• Fluoroquinolone warning
• Penicillin allergy – tips on prescribing in penicillin allergy
• Renal impairment dosing table
• Drug interactions table.
• Visit the Health Products Regulatory Authority (HPRA) website for detailed drug information (summary of product characteristics and patient information leaflets). Dosing details, contraindications and drug interactions can also be found in the Irish Medicines Formulary (IMF) or other reference sources such as British National Formulary (BNF) / BNF for children (BNFC).

Reviewed June 2024