Causes
- In sexually active men aged 14 - 35, the causative organisms are most commonly Chlamydia trachomatis and Neisseria gonorrhoeae, however men who have insertive anal sex may also acquire enteric gram-negative bacteria (such as E. Coli)
- There is weak evidence for the causative role of Mycoplasma genitalium
- In younger and older age groups the causative organisms are more likely to be enteric gram-negative bacteria
- Epididymo-orchitis can also be secondary to a number of other bacterial infections (such as syphilis and tuberculosis) and viral infections (mumps) but this is seen uncommonly in our clinic
Clinical presentation
Typically there is unilateral swelling and tenderness of the epididymis which feels indurated on palpation.
In milder infections there may be no involvement of the testis while in more severe infections, or viral orchitis, the testes are also involved.
The presence of urethral or lower urinary tract symptoms, systemic symptoms and a more gradual onset helps to distinguish epididymo-orchitis from torsion of the testis, but differentiation is frequently difficult and the clinician needs to have a low threshold for referral.
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 with a painful scrotum:
- It most commonly occurs in males under the age of 20 but can occur at any age
- If testicular torsion is suspected, the patient should be referred to an emergency department for urgent surgical assessment
- An ultrasound scan with Doppler is helpful diagnostically but should not delay surgical assessment
Diagnosis
Epididymo-orchitis is a clinical diagnosis, sometimes confirmed on ultrasound scan.
| Test | Site/Specimen | Comments |
|---|---|---|
| NAAT | First void urine | Test for chlamydia and gonorrhoea |
| Gram stain | Urethral swab | Perform if urethral discharge is present (for gram-negative intracellular diplococci) |
| Microscopy, culture and sensitivities | Mid-stream urine | |
| Doppler ultrasound | Testes |
A very useful modality in the diagnosis of epididymo-orchitis and to exclude torsion. It may be used to confirm the clinical impression but it should not delay antibiotic treatment or referral to an emergency department if torsion needs to be excluded |
| Serology | Consider testing for mumps, TB if atypical infection. |
Management
Index patient
Antibiotic treatment depends on the presumed source of infection and should aim to cover the most likely bacterial pathogens.
Simple analgesics, scrotal support, limitation of activity and use of cold packs can be helpful.
Patients with acute epididymo-orchitis on appropriate treatment should generally improve within 48 - 72 hours.
If there is no improvement the diagnosis should be re-evaluated or referral considered.
| Condition | Recommended | Comments |
|---|---|---|
| Epididymo-orchitis likely caused by sexually acquired pathogen |
Doxycycline 100 mg PO, twice daily for 14 days If suspect gonorrhoea, add Ceftriaxone 500 mg IM, stat |
Alternative to Doxycycline: Azithromycin 1 g PO, stat, repeated in 1 week |
| Epididymo-orchitis likely caused by urinary tract pathogen |
Cephalexin 500mg PO, four times a day for 14 days OR Amoxycillin + clavulanate 875+125mg PO, twice daily for 14 days |
Alternative antibiotics: Ciprofloxacin 500mg PO, twice daily for 14 days OR Norfloxacin 400mg PO, twice daily for 14 days |
Disclaimer
We recognise that gender identity is fluid. In our treatment guidelines, the words and language we use to describe genitals and gender are based on the sex assigned at birth.
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.