Epididymitis/orchitis is a topic covered in the 5-Minute Emergency Consult.

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  • Definition: Inflammation or infection of the epididymis
  • Rare in prepubertal boys
  • Pathogenesis:
    • Initial stages:
      • Cellular inflammation begins in vas deferens, descends to epididymis
    • Acute phase:
      • Epididymis is swollen and indurated in upper and lower poles.
      • Spermatic cord thickened
    • Testis may become edematous owing to passive congestion or inflammation.
    • Resolution:
      • May be complete without sequelae
      • Peritubular fibrosis may develop, occluding ductules.
  • Complications:
    • 2/3 of men have atrophy due to partial vascular thrombosis of testicular artery.
    • Abscess and infarction rare (5%)
    • Incidence of infertility with unilateral epididymitis unknown:
      • 50% with bilateral epididymitis

  • Definition: Inflammation or infection of the testicle:
    • Usually from direct extension of the same process within the epididymis
    • Isolated testicular infection is rare:
      • Can result from hematogenous spread of bacteria or following mumps infection
  • Categories:
    • Pyogenic bacterial orchitis secondary to bacterial involvement of epididymis
    • Viral orchitis:
      • Most commonly due to mumps
      • Rare in prepubertal boys; occurs in 20–30% of postpubertal boys with mumps.
      • Occurs 4–6 days after parotitis but can occur without parotitis.
      • Unilateral in 70% of patients
      • Usually resolution in 6–10 days
      • 30–50% of testes involved have residual atrophy; rarely affects fertility
    • Granulomatous orchitis:
      • Syphilis
      • Mycobacterium and fungal diseases
      • Usually occurs in immunocompromised host


  • Children:
    • Most common in children <1 yr or between the ages of 12–15 yr
    • Etiology identified in only 25% of prepubertal boys
    • Coliform or pseudomonal UTI
    • Sexually transmitted diseases rare in prepubertal males
    • Associated with predisposing abnormalities of lower urinary tract
  • Young men, age <35 yr:
    • Usually sexually transmitted
    • Chlamydia trachomatis (28–88%) with severe inflammation with minimal destruction
    • Neisseria gonorrhea (3–28%)
    • Coliform bacteria (7–24%):
      • Highly destructive with tendency for abscess
      • Coliform bacteria more common in insertive partners in anal intercourse
    • Ureaplasma urealyticum (sole organism in only 6% of cases)
  • Older men, age >35 yr:
    • Commonly associated with underlying urologic pathology (benign prostatic hypertrophy, prostate cancer, strictures)
    • May have acute or chronic bacterial prostatitis
    • Coliform bacteria more common (23–67%), especially after instrumentation
    • C. trachomatis (8–80%)
    • Klebsiella and Pseudomonas species
    • N. gonorrhea (15%)
    • Gram-positive cocci
  • Drug related:
    • Amiodarone-induced epididymitis:
      • Usually with amiodarone levels > therapeutic levels
  • Granulomatous:
    • Etiology maybe related to mycobacterial, syphilis, or fungal infections:
      • Mycobacterium tuberculosis is the most common cause of granulomatous disease affecting the epididymis
      • Suspect in HIV patients
      • Urine cultures often negative for M. tuberculosis
  • Vasculitis:
    • Polyarteritis nodosa
    • Behçet disease
    • Henoch–Schönlein purpura

  • Pyogenic bacterial orchitis:
    • Escherichia coli
    • Klebsiella pneumoniae
    • Pseudomonas aeruginosa
    • Staphylococci
    • Streptococci
  • Viral orchitis:
    • Mumps:
      • 20% may develop epididymo-orchitis.
      • Rarely associated with live-attenuated mumps vaccine
  • Coxsackie A and lymphocytic choriomeningitis virus
  • Granulomatous orchitis: Syphilis, mycobacterial and fungal diseases:
    • Suspect in HIV patients
  • Fungal orchitis:
    • Blastomycosis in endemic regions
    • Invasive candidal infections in immunosuppressed hosts
  • Post-traumatic orchitis: Inflammation

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