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 of testis - can be infectious (usually) or non-infectious
  • Infectious

Clinical Features

  • Testicular tenderness, edema
  • May see erythema of overlying scrotum
  • Viral orchitis
    • Abrupt onset of scrotal pain/swelling 4-7 days after onset of parotitis[1]
    • Usually unilateral
  • Fever, tachycardia
  • Inguinal lymphadenopathy
  • Patient uncomfortable while seated

Differential Diagnosis

Testicular Diagnoses


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.


  • Testicular ultrasound
  • Urinalysis and urine culture
  • May also consider GC, Chlamydia cultures


  • Combination of clinical features and results of imaging/UA
  • Ultrasound may show inflammation, epididymitis, and rules out active torsion
  • Urinalysis positive for infection in epididymo-orchitis



  • Generally may be discharged home

See Also


  1. 1.0 1.1 Trojian, Thomas H., Timothy S. Lishnak, and Diana Heiman. "Epididymitis and orchitis: an overview." Am Fam Physician 79.7 (2009): 583-587.