Epididymitis

Aka: Epididymitis

1. Pathophysiology
   1. Ascending infection via vas deferens from prostatic Urethra
2. Causes: By Age
   1. Age <12 years
      1. Idiopathic
      2. Bacterial Urinary Tract Infection (typically Escherichia coli)
      3. Adenovirus
      4. Enterovirus
   2. Age 12 to 35 years old
      1. Neisseria gonorrhoeae
      2. Chlamydia trachomatis
   3. Age >35 years
      1. Bacterial Urinary Tract Infection (typically Escherichia coli)
3. Causes: Infectious
   1. Common
      1. Escherichia coli
      2. Chlamydia trachomatis
      3. NeisseriaGonorrhea
   2. Uncommon
      1. Ureaplasma urealyticum
      2. Proteus mirabilis
      3. KlebsiellaPneumoniae
      4. Pseudomonas aeruginosa
   3. Rare
      1. Mycobacterium tuberculosis
      2. Cytomegalovirus (HIV Infection)
      3. Fungal organisms (HIV Infection or other immunosuppressed condition)
4. Causes: Inflammatory conditions
   1. Post-infectious inflammation (more common in prepubescent boys with 0.1% Incidence)
      1. Mycoplasma pneumoniae
      2. Enterovirus infection
      3. Adenovirus infection
   2. Other inflammatory Epididymitis causes
      1. Medication induced (e.g. Amiodarone)
      2. Vasculitis
5. Risk Factors
   1. General risks
      1. Sexual activity
      2. Strenuous Exercise
      3. Bicycle or motorcycle riding
      4. Prolonged sitting
   2. Additional risks in prepubescent males and those over age 35 years
      1. Urinary tract procedures
      2. Prostatic obstruction (older men)
      3. Meatal stenosis
      4. Posterior Urethral valves (boys)
6. Differential Diagnosis
   1. Testicular Torsion (critical to differentiate, rare outside ages 8 to 35 years and newborns)
   2. Torsion of Testicular Appendage (rare outside ages 7 to 20 years)
   3. Orchitis
7. Symptoms
   1. Gradual onset of unilateral Scrotal Pain
      1. Pain localizes to posterior Testicle
      2. Pain may radiate to opposite Testicle or into lower Abdomen
      3. Contrast with Testicular Torsion where pain is sudden and unilateral
         1. Testicular Torsion pain may recur if torsion is intermittent (rare in Epididymitis)
         2. Orchitis may also present with sudden unilateral Testicular Pain
   2. Symptoms of Urinary Tract Infection (rare in Testicular Torsion)
      1. Fever
      2. Urethral discharge
      3. Urinary frequency or urinary urgency
      4. Dysuria
      5. Hematuria
8. Signs
   1. Epididymis inflammation
      1. Tenderness to palpation at the epididymis, superior and posterolateral to Testicle
      2. Epididymis is enlarged and indurated
   2. Adjacent scrotal and testicular inflammation may occur with Testicular Torsion or infection
      1. Orchitis and Testicular Torsion both cause testicular swelling, scrotal erythema, reactive Hydrocele
   3. Cremasteric Reflex present in both Orchitis and Epididymitis
      1. Absent in Testicular Torsion
   4. Prehn's Sign Positive
      1. Elevation of Scrotum relieves pain of Epididymitis
      2. Does not offer relief, and may exacerbate Testicular Torsion pain
      3. Unreliable as a single test in distinguishing Epididymitis from Testicular Torsion
   5. Testes assume normal position in Epididymitis (and Orchitis)
      1. Contrast with Testicular Torsion where the Testicle is high-riding with transverse orientation
9. Labs
   1. Urinalysis and Urine Culture (first void urine samples are preferred)
      1. Often normal despite Epididymitis
      2. Pyuria (Urethritis) may be present in Epididymitis and absent in Testicular Torsion
         1. Leukocyte esterase positive
         2. Urine White Blood Cells present on microscopy
   2. Inflammation markers are increased in Epididymitis and Orchitis (absent in torsion)
      1. C-Reactive Protein (CRP, processing time may preclude use to triage Ultrasound)
         1. Test Sensitivity (96%)
         2. Test Specificity (92%)
         3. Doehn (2001) Eur Urol 39:215-21
      2. Erythrocyte Sedimentation Rate (ESR)
   3. Sexually Transmitted Disease testing (PCR Urethral swab or first-void urine)
      1. NeisseriaGonorrhea PCR
      2. Chlamydia trachomatis PCR
10. Imaging
    1. Color doppler Ultrasound
       1. Differentiates Epididymitis and Orchitis (increased blood flow) from Testicular Torsion (absent blood flow)
       2. Consider in all cases where Testicular Torsion cannot otherwise be excluded
11. Management: General measures
    1. Relative rest
    2. Scrotal elevation/support
    3. Local Ice Therapy
    4. NSAIDs
12. Management: Antibiotics (same management for immunocompromised patients)
    1. Gonorrhea and Chlamydia Treatment (empirically treat those between ages 14 and 35 years)
       1. Rocephin 250 mg IM for 1 dose and
       2. Doxycycline 100 mg twice daily for 10 days
          1. Zithromax 1g PO for 1 dose has been used as an alternative but is not a CDC recommendation
    2. Urinary tract source treatment (those not sexually active, or outside the 14-35 age range)
       1. Ofloxacin 300 mg orally twice daily for 10 days
       2. Levofloxacin 500 mg orally once daily for 10 days
13. Follow-up Evaluation
    1. Complete Urologic evaluation indications
       1. Child with Epididymitis
          1. Structural or functional urinary abnormality in 39%
       2. Adult with non-STD Epididymitis
14. Prognosis
    1. Inflammation and pain resolve over 2-4 weeks
15. Complications
    1. Orchitis
       1. Contiguous spread from infected epididymis
    2. Chronic Epididymitis
       1. Severe acute Epididymitis
       2. Followed by frequent mild repeat attacks
    3. Fibroplasia
       1. Scarring of epidymis
       2. Patient feels "lump" in Scrotum
16. References
    1. Luzzi (2001) BJU Int 87(8): 747-55
    2. Tojian (2009) Am Fam Physician 79:583-7