STI-associated syndromes guide: Epididymitis

On this page:

• Public health importance
• Common STI-associated etiology
• Clinical manifestations
• Diagnostic testing
• Empiric treatment and management
• Follow-up
• Reporting and partner notification
• References

Public health importance

Acute epididymitis is the most common cause of scrotal pain in adults^{Footnote 1} and is frequently associated with an STI^{Footnote 2Footnote 3}.

Common STI-associated etiology

The probability that epididymitis is caused by a sexually transmitted infection (STI), another infection or a non-infectious cause depends on a person's sexual practises and risk factors for a sexually transmitted and blood-borne infection (STBBI). Acute epididymitis is primarily an infective condition^{Footnote 3Footnote 4}. Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) are the most common causes of acute epididymitis in sexually active people^{Footnote 2Footnote 3}.

Adults with STBBI risk factors

• Common etiology: CT and GC
• Predisposing factors: urethritis caused by an STI

Adults without STBBI risk factors

• Common etiology: coliforms or Pseudomonas aeruginosa
• Predisposing factors: underlying structural pathology, urological procedures or chronic bacterial prostatitis

Enteric bacteria may be a frequent cause of acute epididymitis in sexually active individuals (in all age groups) who practice condomless insertive anal sex ^{Footnote 3}.

Clinical manifestations

Symptoms and signs of epididymitis include:

• Gradual onset of unilateral testicular pain (pain can be bilateral)
• Tenderness to palpation on the affected side
• Palpable swelling of the epididymis
• Urethral discharge
• Hydrocele
• Erythema, edema or both of the scrotum on the affected side
• Fever, chills or both

Symptoms of urethritis may be present in epididymitis caused by a STI.

Consider a diagnosis of testicular torsion in all cases of acute and unilateral testicular pain. Testicular torsion is often associated with sudden and severe onset of pain and requires urgent assessment and management because testicular viability can be compromised. It can occur at any age, but is more frequent in individuals under 20 years.

In children and young adults, it is important to consider non-infectious causes of scrotal swelling, such as trauma. Low grade pain with progression over months or weeks may be indicative of a tumour.

Diagnostic testing

• Obtain first-void urine (FVU) or urethral swab for nucleic acid amplification tests (NAAT) for CT and GC, plus urethral swab for culture for GC (where available).
• Obtain mid-stream urine for culture^{Footnote 5}.
• Doppler ultrasound may be useful to help differentiate epididymitis from testicular torsion or an abscess^{Footnote 5}.

Empiric treatment and management

The decision to treat empirically or to wait for test results should reflect the:

• Severity of the clinical condition
• Probability of infection
• Person's risk factors for a STBBI
• Person's willingness to abstain from sex and to return for test results or follow-up

Consider urgent consultation with an experienced colleague and hospitalization when severe pain or high fever suggests another diagnosis or complicated infection (testicular torsion, testicular infarction, abscess, necrotizing fasciitis)^{Footnote 6}.

Follow-up

Evaluate response to treatment 48 hours after initiation. If there is no clinical improvement, reassess the diagnosis and treatment.

The need for test of cure (TOC) depends on which pathogen is confirmed by laboratory testing. Refer to the etiology-specific guide.

Reporting and partner notification

When treatment is indicated for an STI: notify, evaluate, test and treat (as appropriate) sexual partners. Refer to the etiology-specific guide(s) for guidance on reporting and partner notification.