Epididymo-Orchitis Summary

Age-Based Causes

  • 14-35y: STIs (Chlamydia, Gonorrhea)
  • >35y: Enteric organisms (E. coli)
  • Children: Viral/idiopathic
  • All ages: Consider torsion

Red Flags for Torsion

  • Sudden onset (<6 hours)
  • Nausea/vomiting
  • Absent cremasteric reflex
  • High-riding testis

Key Investigations

  • Urine dipstick/MSU
  • STI NAAT testing
  • Ultrasound if torsion suspected
  • Assess systemic symptoms

Empirical Treatment

  • STI-likely: Ceftriaxone + Doxycycline
  • Enteric-likely: Ofloxacin/Levofloxacin
  • Duration: 10-14 days
  • GUM referral for STI cases

Admission Criteria

  • Systemic sepsis
  • Suspected abscess
  • Diagnostic uncertainty
  • Severe pain/swelling

Epididymo-Orchitis

Definition

Epididymo-orchitis is a clinical syndrome consisting of pain, swelling, and inflammation of the epididymis and/or testis. Over half of cases involve both structures (epididymo-orchitis), while isolated orchitis is rare (most commonly caused by mumps).

Causes by Age Group

Pre-pubertal Children

  • Usually idiopathic/self-limiting
  • Possible viral causes:
    • Adenovirus
    • Enterovirus
  • Rarely enteric organisms (E. coli)

Sexually Active (14-35y)

  • STIs (most common):
    • Chlamydia trachomatis
    • Neisseria gonorrhoeae

Adults >35y/Low-risk

  • Enteric organisms:
    • Escherichia coli
    • Enterococcus faecalis
  • Associated with:
    • UTIs
    • Urological procedures

Other Causes

  • Mumps orchitis (4-8 days post-parotitis)
  • Amiodarone toxicity
  • TB (painless, "string of beads" vas deferens)
  • Anal intercourse (enteric organisms)

Clinical Features

Key Symptoms

  • Gradual onset scrotal pain/swelling
  • Fever, dysuria
  • Urethral discharge (STI-related)
  • Prehn sign (pain relief with elevation)

Examination Findings

  • Unilateral testicular tenderness
  • Epididymal swelling
  • Scrotal erythema/edema
  • Preserved cremasteric reflex

Red Flags for Testicular Torsion

  • Sudden onset (<6 hours)
  • Nausea/vomiting
  • Absent cremasteric reflex
  • High-riding/testicular lie

Investigations

  • Urine tests:
    • Dipstick (leukocytes ± nitrites)
    • MSU for culture (if enteric suspected)
  • STI screening: NAAT for gonorrhoea/chlamydia
  • Imaging: Ultrasound if torsion suspected
  • Avoid: Routine blood tests unless systemic illness

Management

Admission Criteria

  • Systemically unwell/sepsis
  • Suspected abscess/complication
  • Diagnostic uncertainty (vs torsion)

STI-Likely (14-35y)

  • Preferred: Refer to GUM clinic
  • Empirical treatment:
    • Ceftriaxone 1g IM single dose
    • PLUS Doxycycline 100mg BD 10-14d
  • Abstain from sex until treated

Enteric-Likely (>35y)

  • First-line:
    • Ofloxacin 200mg BD 14d
    • OR Levofloxacin 500mg OD 10d
  • Alternative:
    • Co-amoxiclav 500/125mg TDS 10d

Supportive Measures

  • Scrotal support/elevation
  • Analgesia (NSAIDs/paracetamol)
  • Follow-up if no improvement in 3d

Special Cases

Pre-pubertal Children

  • Usually self-limiting
  • Treat UTI if confirmed
  • Consider renal ultrasound (anatomical)

Mumps Orchitis

  • Supportive care only
  • Occurs 4-8d post-parotitis
  • Risk of testicular atrophy

Complications

  • Testicular abscess/infarction
  • Reactive hydrocele
  • Chronic pain (10-15%)
  • Subfertility (especially mumps)