Acute epididymo-orchitis is a clinical syndrome consisting of pain, swelling and inflammation of the epididymis, with or without inflammation of the testes. The most common route of infection is local extension and is mainly due to infections spreading from the urethra (sexually transmitted infections) or from the bladder.¹ Orchitis (infection limited to the testis) is much less common. Chronic epididymitis refers to epididymal pain and inflammation (usually without scrotal swelling) that lasts for more than 6 months.

Aetiology of epididymo-orchitis

• In men under 35 years old, infection is most often due to a sexually transmitted pathogen, e.g. Chlamydia trachomatis and Neisseria gonorrhoeae.²
• In men over 35 years old, infection is most often due to a nonsexually transmitted Gram-negative enteric organism causing urinary tract infections, e.g. Escherichia coli, Pseudomonas spp. Specific risk factors include recent instrumentation or catheterisation.
• However, there is an overlap between these groups and a thorough sexual history is imperative for all age groups.
• Mumps should be considered as an aetiology since the recent epidemic in 2005.¹
• Extrapulmonary tuberculosis (TB) represents 40-45% of TB cases in the UK, but tuberculous epididymo-orchitis is a rare presentation. It is likely to present in patients from high prevalence countries or with a previous history of TB and particularly in patients with immunodeficiency. It is usually a result of disseminated infection and commonly associated with renal TB but can be an isolated finding.
• Ureaplasma urealyticum is found in men with epididymo-orchitis, often in association with N. gonorrhoeae or C. trachomatis infection.
• 12-19% of men with Behçet's disease develop epididymo-orchitis. This is noninfective and thought to be part of the disease process. It is associated with more severe disease.
• Other rare infections (e.g. brucellosis, coccidioidomycosis, blastomycosis, cytomegalovirus and candidiasis) usually occur in immunocompromised hosts.
• Epididymo-orchitis has also been reported as an adverse effect of amiodarone. This is dose-dependent, and usually occurs at doses greater than 200 mg daily.

Aetiology of acute orchitis

• Viral: mumps orchitis is most common. Coxsackievirus type A, varicella, and echoviral infections are rare.
• Bacterial and pyogenic infections: E. coli, Klebsiella, Pseudomonas, Staphylococcus, and Streptococcus species are unusual.
• Granulomatous: syphilis, TB, leprosy, Actinomyces spp., and fungal diseases are rare.
• Trauma.
• Idiopathic.

Epidemiology

• The estimated incidence is 1 in 1,000 men.³
• Acute epididymitis most commonly occurs in patients aged 15-30 years and patients older than 60 years. Prepubertal epididymitis is rare (and testicular torsion is much more common in this age group).
• Mumps orchitis occurs in 20-40% of postpubertal boys with mumps; it is rare in prepubertal boys.

Risk factors

• Common risk factors for gonorrhoea are previous N. gonorrhoeae infection, known contact of gonorrhoea, presence of purulent urethral discharge, men who have sex with men and black ethnicity.¹
• Instrumentation and indwelling catheters are common risk factors for acute epididymitis. Urethritis or prostatitis may also co-exist.
• Structural or functional abnormalities of the urinary tract are common in the group infected with Gram-negative enteric organisms. Adults usually have bladder outlet obstruction or urethral stricture; children may have an ectopic ureter, posterior urethral valves or vesicoureteral reflux.
• Anal intercourse is also a risk factor for infection with enteric pathogens.
• Reflux of infected urine from the prostatic urethra to the epididymis via the ejaculatory ducts and vas deferens may be induced by Valsalva manoeuvre or strenuous exertion. Epididymitis is common in men performing strenuous exertion when there is no opportunity to void, resulting in a full bladder.

Presentation

See also separate article Genitourinary History and Examination (Male).

• Usually presents with unilateral scrotal pain and swelling of relatively acute onset.
• Acute epididymitis is usually unilateral but is bilateral in 5-10% of the patients.
• In sexually transmitted epididymo-orchitis there may be symptoms of urethritis or a urethral discharge.
• There may be a history of symptoms suggesting a urinary tract infection or a history of bacteriuria.
• Mumps usually presents with headache, fever and unilateral or bilateral parotid swelling but may present with epididymitis. Scrotal involvement can occur without systemic symptoms.
• Symptoms suggestive of tuberculous infection include subacute/chronic onset of painless or painful scrotal swelling, associated with systemic symptoms of TB, a scrotal sinus or thickened scrotal skin.

Signs

• Tenderness to palpation on the affected side.
• Palpable swelling of the epididymis starting with the tail at the lower pole of the testis and spreading towards the head at the upper pole of the testis with or without involvement of the testicle.
• There may also be urethral discharge, secondary hydrocele, erythema and/or oedema of the scrotum on the affected side and pyrexia.

Differential diagnosis

• Testicular torsion with ischaemia or infarction.
• Trauma.
• Abscess formation.
• Testicular or epididymal tumour.
• Hydrocele.

Investigations¹

A sexually transmitted cause should always be excluded. The following should be performed:

• Gram-stained urethral smear (even if urethral symptoms are absent), examined microscopically for the diagnosis of urethritis, (5 or more polymorphonuclear leukocytes per high power field x 1000) and presumptive diagnosis of gonorrhoea (Gram-negative intracellular diplococci), or Gram-stained preparation from a centrifuged sample of first passed urine (FPU) for microscopy is an alternative method of diagnosing urethritis (10 or more polymorphonuclear leukocytes per high power field x 1000).
• Urethral swab for N. gonorrhoeae culture and/or FPU or urethral swab for nucleic acid amplification test (NAAT) for N.gonorrhoeae.
• FPU or urethral swab for C. trachomatis NAAT.
• Microscopy and culture of mid-stream specimen of urine (MSU) for bacteria. Urinalysis including nitrite and/or a leukocyte esterase test is helpful, but is not diagnostic.
• Consider HIV testing if there are any risk factors or clinical suspicion.
• If it can be arranged without delay, colour Doppler ultrasound to assess arterial blood flow, may be useful to help differentiate between epididymo-orchitis and torsion of the spermatic cord (but the sensitivity for detecting torsion may not be 100% and this should not delay surgical exploration of the scrotum).

Further Investigations

Other investigations which could be considered include:

• All patients with sexually transmitted epididymo-orchitis should be screened for other sexually transmitted infections.
• Anatomical abnormalities of the urinary tract are common in the group infected with Gram-negative enteric organisms and further investigation of the urinary tract should be considered in all such patients, especially in those older than 50 years.
• When investigating for tuberculous infection, three early morning urine samples should be obtained but these are not always positive for acid-alcohol fast bacilli (AAFB) in the setting of TB epididymitis. Other investigations recommended include intravenous urography, renal tract ultrasound scan and biopsy of the site as well as a chest X-ray to exclude or confirm co-existing respiratory involvement.
• When considering mumps as a possible diagnosis, mumps IgM/IgG serology should be checked.
• There is no role for epididymal aspiration/fine needle aspiration cytology in routine clinical practice. It may be useful in recurrent infection which fails to respond to therapy and if epididymo-orchitis is found at operation and in the case of suspected tuberculous epididymitis.

Management

• If there is any possibility of torsion, arrange urgent urology opinion.
• If there is possible sexually transmitted disease (STD), e.g. younger age, multiple partners or new partner:⁵
  • Refer urgently to a genitourinary clinic for full STD screen, treatment and contact tracing.
  • Advise to avoid unprotected sex until treatment and follow up, including tracing and treating sexual contacts, have been completed.

General advice

• Appropriate rest, analgesia and scrotal support are recommended.
• Non-steroidal anti-inflammatory drugs may be helpful.
• Patients should be advised to abstain from sexual intercourse until they and their partner(s) have completed treatment and follow-up in those with confirmed or suspected sexually transmitted epididymo-orchitis.

Drugs¹

• Empirical therapy should be given to all patients with epididymo-orchitis before culture/NAAT results are available. The antibiotic regimen chosen should be determined in the light of the immediate tests (urethral or FPU smear, urinalysis) as well as age, sexual history including insertive anal intercourse, any recent instrumentation or catheterisation and any known urinary tract abnormalities.
• Antibiotics may need to be varied according to local knowledge of antibiotic sensitivities and changed once the results of cultures and sensitivities are known.
• For epididymo-orchitis most probably due to any sexually transmitted pathogen: ceftriaxone 250 mg intramuscularly single dose, plus doxycycline 100 mg by mouth twice daily for 10-14 days.
• If it is most probably due to chlamydia or other nongonococcal organisms (i.e. where gonorrhoea is considered unlikely as microscopy is negative for Gram-negative intracellular diplococci and no risk factors for gonorrhoea are identified) consider: doxycycline 100 mg by mouth twice daily for 10-14 days or ofloxacin 200 mg by mouth twice daily for 14 days.
• For epididymo-orchitis most probably due to enteric organisms: ofloxacin 200 mg by mouth twice daily for 14 days or ciprofloxacin 500 mg by mouth twice daily for 10 days.
• Corticosteroids have been used in the treatment of acute epididymo-orchitis but have not been shown to be of benefit.
• In those with severe epididymo-orchitis or features suggestive of bacteraemia, inpatient management of fluid and electrolyte balance is required. Intravenous broad-spectrum therapy directed towards coliforms and Pseudomonas aeruginosa should be considered: cefuroxime 1.5 g three times daily with or without gentamicin for 3-5 days until fever subsides; in those with severe allergy to penicillin, use ciprofloxacin 500 mg twice daily.
• For epididymo-orchitis of all causes where the patient is allergic to cephalosporins and/or tetracyclines: ofloxacin 200 mg by mouth twice daily for 14 days.

Sexual partners

Partner notification and treatment is recommended for all patients with epididymo-orchitis secondary to gonorrhoea, chlamydia and nongonococcal urethritis (NGU) or of indeterminate aetiology and subsequent MSU negative.

Follow-up

• If there is no improvement in the patient's condition after 3 days, the diagnosis should be reassessed and therapy re-evaluated.
• Further follow-up is recommended at 2 weeks to assess compliance with treatment, partner notification and improvement of symptoms.
• The swelling and tenderness can persist after antimicrobial therapy is completed but should be significantly improved. Where there is little improvement, further investigations such as an ultrasound scan or surgical assessment should be considered.

Surgical

• Scrotal exploration if a torsion or tumour cannot be ruled out and for the complications of acute epididymitis and orchitis (e.g. abscess, testicular infarction).⁶

Complications

Complications are more often seen in patients with uropathogen-related epididymo-orchitis than sexually transmitted infection-associated epididymo-orchitis.

• Reactive hydrocele.
• Abscess formation and infarction of the testicle (both are rare).
• Infertility - the relationship between epididymo-orchitis and infertility is poorly understood. Men who present with obstructive azoospermia are usually found to have epididymal obstruction when explored for sperm retrieval, which may be a consequence of previous infection.
• Mumps epididymo-orchitis can lead to testicular atrophy. Of those with bilateral orchitis, 13% will have reduced fertility.

Document references

1. Management of epididymo-orchitis, British Association for Sexual Health and HIV (BASHH), June 2010
2. Melekos MD, Asbach HW; Epididymitis: aspects concerning etiology and treatment. J Urol. 1987 Jul;138(1):83-6. [abstract]
3. Sabanegh ES et al; Epididymitis, eMedicine, Apr 2010
4. Galejs LE; Diagnosis and treatment of the acute scrotum. Am Fam Physician. 1999 Feb 15;59(4):817-24. [abstract]
5. Sexually Transmitted Infections in Primary Care, Royal College of General Practitioners (RCGP), 2006
6. Hoppner W, Strohmeyer T, Hartmann M, et al; Surgical treatment of acute epididymitis and its underlying diseases. Eur Urol. 1992;22(3):218-21. [abstract]

Internet and further reading

• Scrotal swellings, Clinical Knowledge Summaries (February 2010)
• Guidelines on Urological Infections, European Association of Urology (March 2009)

Acknowledgements