What are the primary causes of epididymitis in men?

Primary Causes of Epididymitis in Men

The primary causes of epididymitis in men are age-dependent, with sexually transmitted infections being most common in younger men (<35 years) and urinary tract infections caused by enteric organisms predominating in older men (>35 years). 1

Age-Related Etiology

Men Under 35 Years

• Sexually Transmitted Pathogens:

  • Chlamydia trachomatis (most common) 1, 2
  • Neisseria gonorrhoeae 1, 2
  • These infections typically present with concurrent urethritis (often asymptomatic) 1

• Special Population - Men Who Practice Insertive Anal Intercourse:

  • Enteric organisms (especially Escherichia coli) 1
  • These men may have sexually transmitted epididymitis caused by coliform bacteria 1, 2

Men Over 35 Years

• Urinary Tract Pathogens:
  • Gram-negative enteric organisms 1
  • Associated with:
    • Bladder outlet obstruction 2
    • Urinary tract instrumentation or surgery 1
    • Anatomical abnormalities of the urinary tract 1

Children (Under 14 Years)

• Primary Mechanism:
  • Reflux of urine into ejaculatory ducts (most common cause) 2
  • Specific pathogens less well defined in this population

Pathophysiology

The main routes of infection include:

1. Retrograde ascent: Pathogens ascend from the urethra through the vas deferens to the epididymis 3
2. Reflux of urine: Particularly important in older men with bladder outlet obstruction and children 2
3. Direct extension: From adjacent infected structures

Clinical Presentation

• Gradual onset of posterior scrotal pain (distinguishes from testicular torsion) 2, 4
• Unilateral testicular pain and tenderness 1
• Hydrocele and palpable swelling of the epididymis 1
• Often accompanied by urinary symptoms:
  • Dysuria
  • Urinary frequency
  • Fever may be present 4

Diagnostic Approach

For accurate diagnosis and appropriate treatment, the following tests should be performed:

1. Urethral evaluation:

   • Gram-stained smear of urethral exudate (>5 polymorphonuclear leukocytes per oil immersion field indicates urethritis) 1
   • Culture or nucleic acid amplification test for N. gonorrhoeae and C. trachomatis 1

2. Urine studies:

   • Examination of first-void urine for leukocytes if urethral Gram stain is negative 1
   • Culture and Gram-stained smear of uncentrifuged urine 1

3. Additional testing:

   • Syphilis serology and HIV counseling/testing 1

Treatment Considerations

Treatment is based on the likely causative organism according to age:

For men <35 years (suspected STI pathogens):

• Ceftriaxone 250 mg IM in a single dose PLUS
• Doxycycline 100 mg orally twice a day for 10 days 1, 5

For men >35 years (suspected enteric organisms) or those allergic to cephalosporins/tetracyclines:

• Ofloxacin 300 mg orally twice a day for 10 days OR
• Levofloxacin 500 mg orally once daily for 10 days 1, 2, 4

Supportive measures:

• Bed rest, scrotal elevation, and analgesics until fever and local inflammation subside 1

Important Caveats and Pitfalls

1. Distinguishing from testicular torsion:

   • Torsion is a surgical emergency requiring immediate intervention
   • More common in adolescents
   • Presents with sudden onset of severe pain
   • Patients typically lack evidence of inflammation or infection
   • Emergency evaluation is needed when pain onset is sudden and severe 1

2. Treatment failure:

   • Failure to improve within 3 days requires reevaluation of diagnosis and therapy 1
   • Persistent swelling and tenderness after completing antibiotics requires comprehensive evaluation
   • Differential diagnosis includes tumor, abscess, infarction, testicular cancer, tuberculosis, and fungal epididymitis 1

3. Partner management:

   • Sexual partners of patients with STI-related epididymitis should be referred for evaluation and treatment 1

4. Potential complications:

   • Untreated acute epididymitis can lead to infertility and chronic scrotal pain 2
   • Prompt and appropriate treatment is essential to reduce morbidity

By understanding the age-related etiology of epididymitis and providing targeted antimicrobial therapy, clinicians can effectively manage this common condition and prevent complications.