Epididymitis

Background

Scrotal anatomy
Adult testicle with epididymis (left is posterior): A. Head of epididymis, B. Body of epididymis, C. Tail of epididymis, and D. Vas deferens.
  • Inflammation/infection of the epididymis; due to retrograde ascent of pathogens (usually bacterial), the type of which is associated with age
  • Progression of epididymitis results in epididymo-orchitis, now involving testes; isolated bacterial orchitis is rare
  • Often confused with testicular torsion
    • Cremasteric reflex intact in epididymitis, usually absent in torsion
    • Epidididymitis typically more gradual onset and has concurrent lower urinary tract complaints
    • Torsion rarer with older men
  • Chemical epididymitis
    • Consider in the patient with afib and testicular pain
    • Testicular pain and swelling in patients on amiodarone

Clinical Features

  • Pain of gradual onset, peaks at 24hr
    • Can radiate to inguinal and lower abdominal areas
  • Dysuria or urinary frequency/urgency
  • Fever
  • Tenderness of epididymis and/or scrotum, overlying erythema or induration
  • Positive Prehn sign: Pain relieved with elevation of testicle
    • Sensitivity: 91.3%, specificity: 78.3. Does not rule out testicular torsion

Differential Diagnosis

Testicular Diagnoses

Evaluation

Workup

Doppler ultrasound of epididymitis, seen as a substantial increase in blood flow in the left epididymis (top image), while it is normal in the right (bottom image). The thickness of the epididymis (between yellow crosses) is only slightly increased.
Acute epididymo-orchitis. Contrast-enhanced CT (a, b) shows thickened and engorged left spermatic cord, with inhomogeneous vascularisation of the ipsilateral epididymis (thin arrows) and testis (arrows). Ultrasound (c) reveals hypervascularisation of the epididymis (+).
  • Urinalysis
    • Pyuria seen in half of cases
  • Urine culture (children, elderly men)
  • Urine GC/Chlam (urethral discharge or age <40)
  • Ultrasound for equivocal cases
  • Older men should be evaluated for urinary retention

Diagnosis

  • Based on clinical exam or ultrasound

Management

Antibiotics

  • For acute epididymitis likely caused by STI [1]
  • For acute epididymitis most likely caused by STI and enteric organisms (MSM)
  • For acute epididymitis most likely caused by enteric organisms

For persons weighing ≥150 kg, 1 g of ceftriaxone should be administered.

  • If med adherence is an issue [2]

Pediatric Epididymitis[3]

  • Rule out testicular torsion
  • Bed rest to ensure lymphatic drainage
  • Ice packs, acetaminophen, ibuprofen
  • Rarely oral narcotics
  • Pediatric urology follow up outpatient in non-toxic child for possible GU anatomical abnormalities
  • Antibiotics for 10-14 days, with urine culture sent:

Disposition

  • Admit for systemic signs (fever, chills, nausea/vomiting), septic or toxic appearance, epididymal or testicular abscess formation, failure of outpt ABX
  • Discharge with urology follow-up in 1 week if non-toxic

See Also

References

  1. https://www.cdc.gov/std/treatment-guidelines/epididymitis.htm
  2. CDC 2022 guidelines
  3. Richman MN and Bukowski TP. Pediatric Epididymitis: Pathophysiology, Diagnosis, and Management. Infect Urol. 2001;14(2).