II. Definitions

  1. Epididymitis
    1. Inflammation of the epididymis, typically due to Bacterial Infection (esp. Gonorrhea, Chlamydia)
    2. Much more common than Orchitis
  2. Orchitis
    1. Inflammation of the Testicle, typically due to Viral Infection (esp. mumps)
  3. Epididymo-orchitis
    1. Inflammation of both the epididymis and the Testicle

III. Epidemiology

  1. Incidence (U.S.): 1 per 1000
  2. Boys (up to age 13 years old)
    1. Prepubertal Epididymitis is much less common than Testicular Torsion in this age group
    2. Accounts for one-third of Scrotal Pain in prepubertal boys
    3. Mean age of onset 11 years old
    4. Five year recurrence rate: 25%
  3. Men: Acute Epididymitis
    1. Ages 20-39 years old (43% of cases, especially STD for those under age 35 years old)
    2. Ages 40-59 years old (29%)
  4. Men: Chronic Epididymitis
    1. Mean age: 49 years old

IV. Pathophysiology

  1. Ascending infection via vas deferens from prostatic Urethra

V. Causes: Cohort

  1. Age <14 years
    1. Idiopathic
    2. Anatomic abnormalities (e.g. urine reflux into the ejaculatory ducts)
    3. Bacterial Urinary Tract Infection (typically Escherichia coli)
    4. Post-infectious (Mycoplasma pneumoniae, Adenovirus, Enterovirus) or active Viral Infections
    5. Henoch-Schonlein Purpura (bilateral vasculitic Epididymitis, ages 2 to 11 years old)
  2. Age 14 to 35 years old (sexually active)
    1. Neisseria gonorrhoeae
    2. Chlamydia trachomatis
    3. Enterobacteriaciae (uncommon)
  3. Age >35 years
    1. Bacterial Urinary Tract Infection (typically Escherichia coli)
    2. Bladder outlet obstruction (BPH related)
  4. Men who practice insertive anal intercourse
    1. Enteric Bacteria
  5. Human Immunodeficiency Virus
    1. Cytomegalovirus
    2. Salmonella
    3. Toxoplasmosis
    4. Ureaplasma urealyticum
    5. Corynebacterium
    6. Mycoplasma
    7. Mycobacterium tuberculosis
    8. See Fungal organisms below

VI. Causes: Infectious

  1. See Orchitis
  2. Common - Sexually Transmitted Infection (esp. ages 14 to 35 years)
    1. Chlamydia trachomatis
    2. NeisseriaGonorrhea
  3. Common - Non-Sexually Transmitted (esp. over age 35 years)
    1. Escherichia coli
  4. Uncommon
    1. Ureaplasma urealyticum
    2. Proteus mirabilis
    3. KlebsiellaPneumoniae
    4. Pseudomonas aeruginosa
  5. Rare
    1. Mycobacterium tuberculosis
    2. Cytomegalovirus (HIV Infection)
    3. Brucella
    4. Burkholderia pseudomallei (Pseudomonas pseudomallei)
      1. Tropical and subtropical asia (Thailand, Northern Australia)
    5. Fungal organisms (HIV Infection or other immunosuppressed condition)
      1. Histoplasmosis
      2. Coccidiodes

VII. 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
    4. Mumps Virus (see Orchitis)
  2. Other inflammatory Epididymitis causes
    1. Medication induced (e.g. Amiodarone, BCG vaccine)
    2. Immunoglobulin A Vasculitis (Henoch-Schonlein Purpura)
    3. Sarcoidosis
    4. Behcet Syndrome

VIII. Risk Factors

  1. General risks
    1. Sexual activity (esp. history of Sexually Transmitted Infection)
    2. Strenuous Exercise
    3. Bicycle or motorcycle riding
    4. Prolonged sitting
    5. Trauma
  2. Additional risks in prepubescent males and those over age 35 years
    1. Urinary tract procedures
    2. Prostatic obstruction (older men) or other Bladder outlet obstruction
    3. Meatal stenosis
    4. Posterior Urethral valves (boys)
    5. Amiodarone

IX. Differential Diagnosis

  1. Testicular Torsion
    1. Critical to differentiate (uncommon outside ages 8 to 35 years and newborns)
  2. Torsion of Testicular Appendage
    1. Uncommon outside ages 7 to 20 years old
    2. Blue dot sign (blue discoloration of Scrotum over the torsed appendage)
  3. Orchitis
    1. Concurrent with Epididymitis in 58% of cases
  4. Inguinal Hernia
    1. Swollen, tender Scrotum
  5. Testicular Cancer
    1. Pain in up to 15% of cases
    2. Firm, unilateral Nodule contiguous with Testicle

X. 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 and often comorbid with Epididymitis
  2. Symptoms of Urinary Tract Infection may be present (rare in Testicular Torsion)
    1. Fever
    2. Urethral discharge
    3. Urinary Frequency
    4. Urinary urgency
    5. Dysuria
    6. Hematuria

XI. 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. Stroking inner thigh, retracts Testicle
    2. Absent in Testicular Torsion
  4. Prehn's Sign Positive
    1. Elevation of Scrotum relieves pain of Epididymitis
    2. In contrast, with Testicular Torsion, does not offer relief, and may exacerbate 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

XII. 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 (>10 cells per hpf)
      3. Urethral secretions (Gram Stain, gentian violet or methylene blue) with >2 wbc/hpf
  2. C-Reactive Protein (CRP)
    1. Increased in Epididymitis and Orchitis >24 mg/L in most cases
      1. C-RP is typically normal in Testicular Torsion
    2. C-RP processing time may preclude use to triage Ultrasound
    3. Test Sensitivity (96%)
    4. Test Specificity (92%)
    5. Doehn (2001) Eur Urol 39:215-21 [PubMed]
  3. Sexually Transmitted Disease testing (PCR Urethral swab or first-void urine)
    1. NeisseriaGonorrhea PCR
    2. Chlamydia Trachomatis PCR

XIII. Imaging: Color doppler Scrotal Ultrasound

  1. Indications
    1. Consider in all cases where Testicular Torsion cannot otherwise be excluded
    2. Differentiates Epididymitis and Orchitis (increased Blood Flow) from Testicular Torsion (absent Blood Flow)
  2. Epididymitis
    1. Epididymis with increased Blood Flow, hyperemia and swelling
  3. Testicular Torsion
    1. Decreased or absent testicular Blood Flow
  4. Torsion of appendix Testis
    1. Appendage spherical and >5mm
    2. Increased periappendiceal Blood Flow
  5. Testicular Cancer
    1. Distinct Testicular Mass

XIV. Management: General measures

  1. Relative rest
  2. Scrotal elevation/support
  3. Local Ice Therapy
  4. NSAIDs

XV. Management: Antibiotics (same management for Immunocompromised patients)

  1. Background
    1. Ciprofloxacin alone is not considered adequate coverage for Epididymitis (Chlamydia resistance)
    2. Children 2-14 yo should typically only be treated with antibiotics if positive Urinalysis or Urine Culture
  2. Gonorrhea and Chlamydia Treatment (empirically treat those between ages 14 and 35 years)
    1. Also treat all sexual contacts within last 60 days (see below)
    2. Gonorrhea management
      1. Ceftriaxone 500 mg IM/IV for 1 dose (1 gram IM/IV if weight > 150 kg, dose increased in 2020) OR
      2. Gentamicin 240 mg IM and Azithromycin 2 g orally for one dose OR
      3. Cefixime 800 mg orally once (an alternative but NOT recommended due to Antibiotic Resistance)
    3. Chlamydia management
      1. Doxycycline 100 mg twice daily for 10 days (preferred as of 2020) OR
      2. Azithromycin 1 g orally for 1 dose (NOT recommended) OR
      3. Levofloxacin 500 mg orally twice daily for 10 days
        1. Indicated for insertive anal intercourse (Chlamydia and enteric bacteric coverage)
    4. References
      1. Cyr (2020) MMWR Morb Mortal Wkly Rep 69(50): 1911-6 [PubMed]
        1. https://www.cdc.gov/mmwr/volumes/69/wr/mm6950a6.htm
  3. Urinary tract source treatment (those not sexually active, or outside the 14-35 age range)
    1. First-line agents
      1. Ofloxacin 300 mg orally twice daily for 10 days OR
      2. Levofloxacin 500 mg orally once daily for 10 days
    2. Alternative agents
      1. Amoxicillin-Clavulanate (Augmentin) 875/125 orally twice daily OR
      2. Trimethoprim-Sulfamethoxazole (Septra, Bactrim) DS 1 orally twice daily for 10 days
        1. Avoid if local resistance >20%
    3. Refractory, severe cases
      1. Piperacillin-Tazobactam (Zosyn) 4.5 g IV every 6 hours OR
      2. Ceftriaxone 2 g IV every 24 hours
  4. Combined risks of STD and urinary tract source (anal intercourse with either gender)
    1. Ceftriaxone 500 mg IM for 1 dose AND
    2. Ofloxacin or Levofloxacin at doses above

XVI. Management: Idiopathic Chronic Epididymitis

  1. Assumes negative evaluation as above and trial of empiric antibiotics
  2. Initial trial for 2 weeks
    1. General measures above for supportive care
    2. NSAIDs for 2 weeks
  3. Failed general measures
    1. Tricyclic Antidepressants (e.g. Amitriptyline)
    2. Gabapentin (Neurontin)
    3. Consider Chronic Pain Management referral
    4. Consider referred pain

XVII. Management: Follow-up

  1. Child (ages <14 years old) with Epididymitis
    1. Structural or functional urinary abnormality in 39%
    2. Pediatric urology Consultation recommended
  2. Adult >50 years old with non-STD Epididymitis
    1. Evaluate for Benign Prostatic Hyperplasia (Bladder outlet obstruction)
  3. Sexually Transmitted Infection
    1. Treat all sexual contacts within last 60 days (see Expedited Partner Treatment)
    2. Repeat screening for new STD in 3 months

XVIII. Prognosis

  1. Symptoms improve over first 2-3 days
  2. Inflammation and pain resolve over 2-4 weeks

XIX. Complications

  1. Orchitis
    1. Contiguous spread from infected epididymis (occurs in 58% of Epididymitis cases)
  2. Chronic Epididymitis
    1. Severe acute Epididymitis
    2. Followed by frequent mild repeat attacks
    3. See management above
  3. Fibroplasia
    1. Scarring of epidymis
    2. Patient feels "lump" in Scrotum

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Related Studies

Ontology: Epididymitis (C0014534)

Definition (CSP) inflammation of the epididymis, convoluted cordlike structure attached to the posterior of the testis.
Definition (MSH) Inflammation of the EPIDIDYMIS. Its clinical features include enlarged epididymis, a swollen SCROTUM; PAIN; PYURIA; and FEVER. It is usually related to infections in the URINARY TRACT, which likely spread to the EPIDIDYMIS through either the VAS DEFERENS or the lymphatics of the SPERMATIC CORD.
Concepts Disease or Syndrome (T047)
MSH D004823
ICD10 N45.1
SnomedCT 197998003, 197993007, 155914009, 31070006
English Epididymitides, Epididymitis, EPIDIDYMITIS, Epididymitis NOS, Epididymitis unspecified, epididymitis, epididymitis (diagnosis), Epididymitis [Disease/Finding], Epididymitis NOS (disorder), Epididymitis unspecified (disorder), Epididymis inflamed, Inflammation of epididymis, Epididymitis (disorder), epididymis; inflammation, inflammation; epididymis, Epididymitis, NOS
French EPIDIDYMITE, Epididymite SAI, Épididymite
Portuguese EPIDIDIMITE, Epididimite NE, Epidemite, Epididimite
Spanish EPIDIDIMITIS, Epididimitis NEOM, epididimitis no especificada, epididimitis, SAI, epididimitis no especificada (trastorno), epididimitis, SAI (trastorno), epididimitis (trastorno), epididimitis, Epididimitis
Dutch epididymitis NAO, epididymis; ontsteking, ontsteking; epididymis, epididymitis, Epididymitis
German Epididymitis NNB, NEBENHODENENTZUENDUNG, Epididymitis, Nebenhodenentzündung
Italian Epididimite NAS, Epidimite, Epididimite
Japanese 精巣上体炎, 精巣上体炎NOS, セイソウジョウタイエンNOS, セイソウジョウタイエン
Swedish Bitestikelinflammation
Czech nadvarle - zánět, epididymitida, Epididymitida, Epididymitida NOS
Finnish Lisäkivestulehdus
Polish Zapalenie najądrza
Hungarian Mellékhere-gyulladás, Epididymitis k.m.n.
Norwegian Epididymitt, Betennelse i bitestikkel

Ontology: Epididymo-orchitis (C0149881)

Concepts Disease or Syndrome (T047)
ICD9 604.90, 604
ICD10 N45 , N45.3
SnomedCT 198001001, 198003003, 24084007, 198004009, 155917002, 155913003, 155915005, 197983000
English Epididymo-orchitis NOS, Epididymo-orchitis unspecified, Orchitis and epididymitis NOS, Epididymo-orchitis, orchitis with epididymitis, orchitis with epididymitis (diagnosis), Orchitis/epididymit NOS, epididymoorchitis, orchitis epididymitis, epididymitis orchitis, epididymo-orchitis, epididymo orchitis, Epididymo-orchitis NOS (disorder), Orchitis and epididymitis NOS (disorder), Epididymo-orchitis (disorder), Epididymo-orchitis unspecified (disorder), Orchitis and epididymitis, Orchitis and epididymitis (disorder), Orchitis/epididymitis, Epididymo-orchitis, NOS, Orchitis and epididymitis, unspecified
Dutch epididymoorchitis, orchitis en epididymitis, orchitis en epididymitis, niet-gespecificeerd, epididymoorchitis NAO, Orchitis/epididymitis, Orchitis en epididymitis
French Orchite et épididymite, non précisées, Orchi-épididymite, Orchite et épididymite, Orchi-épididymite SAI
German Orchitis und Epididymitis, Epididymo-Orchitis, Epididymo-Orchitis NNB, Orchitis und Epididymitis, unspezifisch
Italian Orchiepididimite, Orchite ed epididimite, non specificata, Orchite ed epididimite, Orchiepididimite NAS
Portuguese Epididimorquite, Orquite e epididimite, Orquite e epididimite NE, Epididimo-orquite NE
Spanish Orquitis y epididimitis, Epididimoorquitis NEOM, Orquitis y epididimitis no especificadas, Epididimoorquitis, orquiepididimitis, no especificada (trastorno), Orchitis and epididymitis NOS, orquiepididimitis, orquiepididimitis, no especificada, epididimorquitis, SAI (trastorno), orquiepididimitis (trastorno), orquitis y epididimitis, SAI (trastorno), orquitis y epididimitis, SAI, epididimorquitis, SAI, orquitis y epididimitis (trastorno), orquitis y epididimitis
Czech Epididymoorchitida, Orchitida a epididymitida, blíže neurčená, Epididymoorchitida NOS, Orchitida a epididymitida
Korean 고환염 및 부고환염
Japanese 精巣・精巣上体炎, セイソウセイソウジョウタイエン, 精巣・精巣上体炎NOS, セイソウセイソウジョウタイエンNOS
Hungarian Epididymo-orchitis, Orchitis és epididymitis, nem meghatározott, Epididymo-orchitis k.m.n., Orchitis és epididymitis

Ontology: Infective epididymitis (C0729593)

Concepts Disease or Syndrome (T047)
SnomedCT 312224002
English Infective epididymitis, Infective epididymitis (disorder)
Spanish epididimitis infecciosa (trastorno), epididimitis infecciosa