Epididymitis and Orchitis

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Epididymitis refers to inflammation of the epididymis, the structure at the back of the testicle responsible for sperm storage. Orchitis refers to inflammation of the testicle itself. These conditions can occur independently but often coexist as epididymo-orchitis.

Aetiology

1. Infectious Causes:

  • Sexually transmitted infections (STIs):
    • Chlamydia trachomatis (most common in men <35 years).
    • Neisseria gonorrhoeae (often coexists with urethritis).
  • Non-STI bacterial infections:
    • Escherichia coli (common in older men, often linked to urinary tract infections or catheterisation).
    • Pseudomonas (in immunocompromised individuals).
  • Viral:
    • Mumps virus (most common viral cause, can lead to infertility).
    • Coxsackievirus and echovirus.
  • Fungal (rare):
    • Candida species (in immunocompromised patients).

2. Non-Infectious Causes:

  • Trauma (e.g., scrotal injury).
  • Autoimmune conditions (e.g., sarcoidosis, vasculitis).
  • Reflux of urine into the epididymis (associated with heavy lifting or Valsalva manoeuvres).

Pathophysiology

  • Pathogens enter via the urethra and ascend through the vas deferens, leading to inflammation.
  • Inflammatory response causes swelling, pain, and tenderness.
  • If untreated, infection may extend to the testicle, leading to orchitis.
  • Severe cases may result in abscess formation, testicular infarction, or infertility.

Risk Factors

  • Unprotected sexual intercourse (for STI-related cases).
  • History of STIs.
  • Urinary tract infections (common in older men).
  • Indwelling urinary catheter or recent instrumentation.
  • Prostatitis.
  • Vasectomy (rare but possible complication).

Signs and Symptoms

Localised Symptoms:

  • Scrotal pain: unilateral, gradually worsening.
  • Swelling: localised to the epididymis but may involve the whole testicle.
  • Scrotal erythema: redness and warmth.
  • Dysuria: burning sensation during urination (if associated with urethritis).
  • Urethral discharge: suggestive of STI-related cause.

Systemic Symptoms:

  • Fever and chills: more common in bacterial infections.
  • Mumps-related orchitis: often preceded by parotitis.

Investigations

  • Urine dipstick: may show leukocytes and nitrites if UTI-related.
  • Urine culture: identifies bacterial infection.
  • First-void urine sample: NAAT testing for Chlamydia trachomatis and Neisseria gonorrhoeae.
  • Scrotal ultrasound: differentiates from testicular torsion; may show increased blood flow.
  • STI screen: if risk factors are present.
  • Blood tests: FBC (raised WCC suggests infection), CRP (inflammation marker).

Management

1. Empirical Antibiotic Treatment (Before Results):

  • Sexually transmitted (under 35 years):
    • Ceftriaxone 1g IM (single dose) + Doxycycline 100mg BD for 10 days.
    • Alternative: Azithromycin 1g PO single dose + Ofloxacin 400mg BD for 10 days.
  • Non-STI related (older men, UTI-associated):
    • Ciprofloxacin 500mg BD for 10–14 days.
    • Alternative: Levofloxacin 500mg OD for 10–14 days.

2. Supportive Treatment:

  • Scrotal elevation: reduces pain and swelling.
  • Analgesia: paracetamol and NSAIDs for pain relief.
  • Rest and hydration: encouraged during acute phase.
  • Avoid sexual activity: until treatment is complete.

3. Partner Notification and STI Screening:

  • All recent sexual partners should be tested and treated.
  • Advise condom use and safe sex practices.

4. Referral Criteria:

  • Severe or worsening symptoms despite treatment.
  • Suspected testicular torsion (requires urgent urological review).
  • Abscess formation (may require surgical drainage).
RenalmypanotesEpididymitis and Orchitis