What are the causes and recommended management for epididymitis?

Epididymitis: Causes and Management

For sexually active men under 35 years, treat empirically with ceftriaxone 1g IM plus doxycycline 100mg twice daily for 10 days; for men over 35 years or those with urinary tract risk factors, use ofloxacin or levofloxacin alone for 10 days.

Etiology by Age and Risk Factors

The causative organisms of epididymitis follow predictable patterns based on patient demographics:

Men <35 Years (Sexually Active)

• Primary pathogens: Chlamydia trachomatis and Neisseria gonorrhoeae 1
• These account for the majority of cases in this age group
• Sexually transmitted epididymitis typically accompanies urethritis, which is often asymptomatic 1

Men Who Practice Insertive Anal Intercourse

• Enteric organisms, particularly Escherichia coli, are common 1
• Requires broader coverage against gram-negative organisms

Men >35 Years

• Gram-negative enteric organisms predominate, especially E. coli 1
• Usually associated with urinary tract infections
• Risk factors include:
  • Recent urinary tract instrumentation or surgery
  • Anatomical abnormalities of the urinary tract
  • Bladder outlet obstruction 1

Recent molecular diagnostic studies confirm that bacterial pathogens are identified in up to 88% of antibiotic-naive patients, with E. coli accounting for 56% of cases 2. Importantly, sexually transmitted infections are not restricted to younger patients and were found in 14% of cases across all age groups 2.

Diagnostic Evaluation

Critical First Step: Rule Out Testicular Torsion

Testicular torsion is a surgical emergency that must be excluded immediately 1. Consider torsion when:

• Onset of pain is sudden
• Pain is severe
• Patient is an adolescent
• No evidence of inflammation or infection on initial testing
• If questionable, consult a specialist immediately—testicular viability is time-dependent 1

Clinical Presentation

Typical features include 1:

• Unilateral testicular pain and tenderness (100% of cases)
• Palpable swelling of the epididymis
• Hydrocele may be present
• Testis in anatomically normal position

Required Diagnostic Tests

Perform the following before initiating treatment 1:

1. Gram-stained smear of urethral exudate or intraurethral swab

   • Diagnoses urethritis (≥5 polymorphonuclear leukocytes per oil immersion field)
   • Presumptive diagnosis of gonococcal infection

2. Nucleic acid amplification test (NAAT) or culture

   • Test intraurethral swab or first-void urine
   • For N. gonorrhoeae and C. trachomatis

3. First-void urine examination

   • If urethral Gram stain is negative
   • Culture and Gram-stained smear of uncentrifuged urine

4. Syphilis serology and HIV testing 1

Empirical Antibiotic Treatment

Start empirical therapy immediately—do not wait for culture results 1. Treatment prevents microbiologic cure, improves symptoms, prevents transmission, and decreases complications like infertility and chronic pain.

For Sexually Transmitted Epididymitis (Age <35 or STI Risk Factors)

Recommended Regimen 1:

• Ceftriaxone 250mg IM single dose
• PLUS
• Doxycycline 100mg orally twice daily for 10 days

Note: The 2020 UK BASHH guideline recommends ceftriaxone 1g IM to ensure coverage of gonorrhea strains with reduced susceptibility 3. The 2024 EAU guideline also supports 1g dosing 4.

For Men Who Practice Insertive Anal Intercourse

Recommended Regimen 1:

• Ceftriaxone 250mg IM single dose
• PLUS
• Levofloxacin 500mg orally daily for 10 days OR Ofloxacin 300mg orally twice daily for 10 days

This provides coverage for both STIs and enteric organisms.

For Enteric Organism Epididymitis (Age >35, Urinary Tract Risk Factors)

Recommended Regimen 1:

• Ofloxacin 300mg orally twice daily for 10 days OR
• Levofloxacin 500mg orally daily for 10 days

Use this regimen for patients with:

• Age >35 years
• Recent urinary tract instrumentation
• Known urinary tract abnormalities
• Positive urine dipstick for leukocytes and nitrites
• No sexual activity or STI risk factors

For Cephalosporin or Tetracycline Allergy

Alternative Regimen 1:

• Ofloxacin 300mg orally twice daily for 10 days

Adjunctive Therapy

All patients should receive 1:

• Bed rest until fever and inflammation subside
• Scrotal elevation
• Analgesics

These measures are recommended until fever and local inflammation have resolved.

Hospitalization Criteria

Consider hospitalization when 1:

• Severe pain suggests alternative diagnoses (torsion, testicular infarction, abscess)
• Patient is febrile
• Concern about medication compliance
• Immunocompromised status

Follow-Up and Treatment Failure

Reassess within 3 days if no improvement 5. Failure to improve requires reevaluation of both diagnosis and therapy.

If swelling and tenderness persist after completing antibiotics, comprehensive evaluation is needed for 5:

• Tumor
• Abscess
• Testicular infarction
• Testicular cancer
• Tuberculous or fungal epididymitis

Management of Sexual Partners

For epididymitis caused by or suspected to be caused by N. gonorrhoeae or C. trachomatis 5:

• Refer sex partners for evaluation and treatment
• Refer partners with contact within 60 days preceding symptom onset
• Instruct patients to avoid sexual intercourse until both patient and partner(s) complete therapy and are asymptomatic

Special Populations

HIV-Infected Patients

• Treat with the same regimens as HIV-negative patients 5
• However, fungi and mycobacteria are more likely causes in immunosuppressed patients 5
• Consider broader differential if standard therapy fails

Key Clinical Pitfalls

1. Do not assume age-based etiology is absolute: STIs were found in 14% of cases across all age groups in recent studies 2
2. Do not delay treatment for culture results: Empiric therapy is indicated immediately 1
3. Do not miss testicular torsion: Always consider this diagnosis first, especially in adolescents with sudden severe pain 1
4. Do not underdose ceftriaxone: Consider 1g dosing for gonorrhea coverage given emerging resistance 4, 3
5. Do not forget partner treatment: This prevents reinfection and transmission 5