Acute Epididymo-Orchitis

Acute epididymo orchitis is inflammation of the epididymis, usually with involvement of the testis (orchitis), presenting with acute scrotal pain, swelling and often fever. Acute means symptoms for less than 6 weeks; beyond that it is chronic epididymitis.

• Causes depend on age and sexual risk:
  • Men under 35 and sexually active: Chlamydia trachomatis and Neisseria gonorrhoeae (sexually transmitted), occasionally Mycoplasma genitalium.
  • Men over 35, or men who have insertive anal sex: enteric Gram negative organisms (Escherichia coli, Klebsiella, Proteus, Pseudomonas) from urinary tract infection or outlet obstruction, instrumentation or catheterisation.
  • Viral: mumps (orchitis 2 to 10 days after parotitis in 15 to 30 percent of post-pubertal men, bilateral in about 15 to 30 percent of these) and other viruses in children.
  • Non-infective: amiodarone (epididymitis), vasectomy related, Behçet disease, sarcoidosis, trauma, tuberculosis, brucellosis.
• Complications: abscess, testicular infarction, chronic epididymitis or pain, reduced fertility (especially mumps orchitis and bilateral disease), hydrocele and pyocele.
• The critical differential is testicular torsion, a surgical emergency (salvage rate falls steeply after 6 hours), and torsion of the testicular appendage.

• Gradual onset (over hours to days) of unilateral scrotal pain, swelling and tenderness, often radiating to the groin or lower abdomen; fever; dysuria, urethral discharge or frequency.
• Epididymis is tender, swollen and indurated at the posterior testis; later the testis and epididymis merge. Scrotal erythema and reactive hydrocele. Cremasteric reflex preserved. Prehn sign (relief of pain on elevating the testis) is unreliable and should not be used to exclude torsion.
• Urethral discharge or meatal erythema in sexually transmitted disease. Parotid swelling in mumps. Prostatic tenderness in older men.
• Red flags (consider torsion or sepsis): sudden severe pain, nausea and vomiting, high riding horizontal testis, absent cremasteric reflex, age 12 to 18, previous similar self-resolving episodes, systemic sepsis, immunosuppression, diabetes, testicular mass, Fournier gangrene features (crepitus, rapidly spreading erythema, necrosis).

• Clinical, with urgent surgical referral if torsion cannot be excluded.
• First catch urine and urethral swab (or first void urine) for nucleic acid amplification test for chlamydia and gonorrhoea, and for Mycoplasma genitalium; urethral Gram stain; midstream urine microscopy and culture; blood cultures if febrile.
• Bloods: full blood count, CRP, urea and creatinine; HIV and syphilis serology when sexually transmitted infection is possible.
• Scrotal Doppler ultrasound when diagnosis is unclear or torsion, abscess or tumour is possible: epididymis enlarged and hypervascular with increased flow (torsion shows reduced or absent flow).
• Mumps IgM or PCR on saliva or serum in suspected mumps orchitis.
• Older men or recurrent episodes: renal tract ultrasound with post-void residual, flow rate, and cystoscopy if outflow obstruction suspected. Tuberculosis workup in chronic, sterile pyuria.

• Analgesia and supportive: paracetamol 1 g orally every 6 hours (maximum 4 g per day); ibuprofen 400 mg orally three times daily with food (or naproxen 500 mg twice daily) for 5 to 7 days; scrotal support and elevation; ice packs; rest; avoid sexual intercourse until treatment completed and partners treated.
• Likely sexually transmitted organism (under 35 or urethral discharge):
  • Ceftriaxone 1 g intramuscularly as a single dose plus doxycycline 100 mg orally twice daily for 10 to 14 days.
  • If Mycoplasma genitalium is positive or doxycycline fails, moxifloxacin 400 mg orally once daily for 10 days after resistance testing.
  • Partner notification and treatment, test for HIV, syphilis and hepatitis B, and repeat testing at 3 months.
• Likely enteric organisms (over 35, insertive anal sex, recent instrumentation, positive urine culture):
  • Ofloxacin 200 mg orally twice daily for 14 days; or levofloxacin 500 mg orally once daily for 10 days; or ciprofloxacin 500 mg orally twice daily for 10 to 14 days. Reserve fluoroquinolones for when alternatives are unsuitable because of tendon, neuropsychiatric, aortic aneurysm and QT risks.
  • Alternatives where fluoroquinolones are unsuitable: co-amoxiclav 625 mg orally three times daily for 10 to 14 days (if sensitive); or trimethoprim 200 mg orally twice daily for 14 days (if sensitive).
  • Men who have insertive anal sex: ceftriaxone 1 g intramuscularly single dose plus ofloxacin 200 mg orally twice daily for 14 days.
• Severe infection, sepsis or abscess: admit; intravenous ceftriaxone 1 to 2 g once daily or piperacillin tazobactam 4.5 g every 8 hours, adjusted to culture; surgical drainage for abscess; orchidectomy for infarction.
• Mumps orchitis: supportive care, analgesia, scrotal support; short course of prednisolone 40 mg orally daily for 5 days is used by some clinicians for severe bilateral orchitis but evidence is limited. Counsel on fertility. Notify the public health authority.
• Amiodarone related epididymitis: dose reduction or stop with cardiology advice.
• Follow up at 2 to 4 weeks (reassess pain and swelling); persistent swelling beyond 6 weeks needs ultrasound to exclude tumour, abscess or tuberculosis. Offer semen analysis after bilateral or severe disease if fertility is a concern.