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Orchitis and Epididymo-Orchitis

Last updated Dec. 13, 2018

Approved by: Krish Tangella MD, MBA, FCAP

Orchitis is defined as the inflammation of the testes. Isolated inflammation of the testis is commonly caused by associated mumps infection (a viral infection of the parotid glands). Epididymis is a tightly coiled structure at the posterior aspect of the testes.

What are the other Names for this Condition? (Also known as/Synonyms)

  • Epididymo-Orchitis
  • Orchitis, NOS
  • Testicular Inflammation

What is Orchitis and Epididymo-Orchitis? (Definition/Background Information)

  • Orchitis is defined as the inflammation of the testes. Isolated inflammation of the testis is commonly caused by associated mumps infection (a viral infection of the parotid glands).
  • Epididymis is a tightly coiled structure at the posterior aspect of the testes. It is the place where sperms get matured and stored. Spermatic cord arises from the epididymis and then joins the urethra. Epididymitis is an inflammation of the epididymis. Epididymitis if severe affects the adjoining testis and cause orchitis, so it is together called as epidydimo-orchitis.
  • Acute epididymitis is characterized by the onset of epididymal pain and swelling over a period of several days. Chronic epididymitis is characterized by epididymal pain and inflammation that lasts more than 6 weeks and may be accompanied by scrotal indurations. 
  • Some of the risk factors associated with epididymo-orchitis are multiple sexual partners, men with prostate enlargement, and trans urethral procedures (procedures done by passing the scope through urethra)
  • Common signs and symptoms associated with epididymo-orchitis are pain and swelling in the testes and epididymis. Complications that may arise due to the condition include formation of abscess, testicular atrophy, and sterility
  • The prognosis of epididymo-orchitis is generally good with appropriate diagnosis and treatment, which is through suitable antibiotics

Who gets Orchitis and Epididymo-Orchitis? (Age and Sex Distribution)

  • Orchitis associated with mumps usually occurs in children less than 10 years of age
  • Epididymitis can occur in any age group
  • The causes of the epididymitis can vary according to each age group

What are the Risk Factors for Orchitis and Epididymo-Orchitis? (Predisposing Factors)

Risk factors associated with Orchitis and Epididymo-Orchitis are:

  • Multiple sexual partners
  • Men with prostate enlargement
  • Trans urethral procedures (procedures done by passing a scope through the urethra)
  • Children who are not vaccinated against mumps
  • Children with structural abnormality of the urinary tract

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Orchitis and Epididymo-Orchitis? (Etiology)

Causes of acute orchitis:

  • Viral infection: Mumps orchitis was once the most common cause. However, since the introduction of the mumps vaccine in 1985, this has been virtually eliminated
  • Bacterial and pyogenic infections: Infections with E coli, Klebsiella species, Pseudomonas species, Staphylococcus species, and Streptococcus species are usually associated with epididymitis
  • Granulomatous: Treponema pallidum, M. tuberculosis, Mycobacterium leprae, Actinomyces, and fungal diseases are rare these days
  • Trauma
  • Idiopathic: In some cases, the cause is unknown

With regard to a viral etiology (cause), roughly one-third of the post-pubertal boys with mumps have concomitant orchitis. Coxsackievirus type A, varicella, echoviral, adenoviral, enteroviral, influenzal, and parainfluenzal infections are rare.

Causes of epididymitis:

  • The exact cause of the condition is not known. It is thought to be caused by retrograde passage of urine from the prostatic urethra into the ejaculatory duct, and then into the epididymitis. This is precipitated by any trans-urethral or bladder procedures and any strenuous activities when the bladder is full
  • In older males (greater than 40 years), any obstruction to the urethra caused by enlargement of prostate gland can precipitate retrograde passage of urine into the epididymus
  • Organisms causing epidydimitis: These include E. coli, Pseudomonas species, Proteus species, Klebsiella species, etc. in children and men older than 35 yrs
  • Chlamydia, Neisseria gonorrhoea, Treponema pallidum, Tichomonial species, and Gardnerella vaginalis are all common in sexually-active males and those younger than 35 yrs
  • Tuberculous epididymitis, even though it is prevalent only in certain endemic areas, is the most common type of urogenital tuberculosis
  • Other rare infections (such as brucellosis, coccidioidomycosis, blastomycosis, cytomegalovirus, candidiasis, CMV in human immunodeficiency virus infection) have been implicated in epididymitis, but usually occur in immunocompromised hosts
  • In men undergoing vasectomy, about 1 in 1000 individuals may complain of pain over the epididymis. This is due to accumulation of semen causing back pressure on the epididymis
  • Amiodarone, a drug used for cardiac arrhythmias concentrates in the epididymis. The concentration in the epididymis is 300 times more than that in blood. In those taking very high doses, this leads to formation of amiodarone antibodies, which eventually attack the epididymis
  • Sarcoidosis affects the genitourinary system in up to 5% of the cases, typically presenting with epididymal nodules

What are the Signs and Symptoms of Orchitis and Epididymo-Orchitis?

The signs and symptoms associated with orchitis are:

  • Swelling and pain of the testis (which is usually unilateral)
  • Formation of reactive hydrocele (accumulation of fluid around the testis)
  • Epididymis is not a painful condition
  • Orchitis is found in association with acute epididymitis in 20-40% of the patients

The signs and symptoms associated with epididymitis are:

  • Swelling and tenderness of the epididymis
  • Improvement of pain on lifting the testis and epididymis (Phren’s sign). This sign is absent in torsion of testis
  • Normal cremasteric reflex in contrast to torsion
  • Redness and inflammation of the scrotal skin
  • Tuberculous epididymitis can present with draining sinus on the scrotum and beaded appearance of the spermatic duct

How is Orchitis and Epididymo-Orchitis Diagnosed?

The diagnosis of Orchitis and Epididymo-Orchitis may involve the following tests and procedures:

  • Complete evaluation of medical history along with a thorough physical exam
  • Urinalysis for pyuria (the presence of pus cells) or bacteriuria (the presence of bacteria)
  • Urine culture may be performed for prepubertal and elderly patients
  • Complete blood count (CBC) - increased WBCs may be seen
  • Gram stain of urethral discharge, if present
  • Urethral culture, nucleic acid hybridization, and nucleic acid amplification tests: These tests can aid in the detection of N. gonorrhoeae and C. trachomatis
  • Performance of syphilis and HIV testing in patients with a suspicion of sexually-transmitted etiology
  • Doppler ultrasonography: It is done to rule-out testicular torsion and to also evaluate chronic epididymitis

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Orchitis and Epididymo-Orchitis?

Complications of mumps orchitis could include:

  • Hypogonadotropic hypogonadism (low testicular function and low testosterone) can occur as a result of testicular atrophy, which is observed in 30-50% of the patients
  • Sterility occurs in 7-13% of all affected patients
  • Mumps orchitis is not associated with the development of testicular tumors

Complications of acute epididymitis and bacterial orchitis could include:

  • Scrotal abscess and pyocele (pus surrounding the testis)
  • Testicular infarction: Cord swelling can limit testicular blood flow
  • Fertility issues
  • Testicular atrophy: The testis becomes small and functionless
  • Cutaneous fistulization (draining) from rupture of an abscess (especially seen in TB)
  • Recurrence, chronic epididymitis

How is Orchitis and Epididymo-Orchitis Treated?

Treatment of epididymo-orchitis includes:

  • Antibiotics for 4 to 6 weeks against chlamydia and Neisseria gonorrhoea are recommended for those with suspected sexually-transmitted condition. Antibiotics have to be administered to the sexual partners also, to prevent recurrence of the condition
  • In children and pre-pubertal males, antibiotics are given to those with pyuria and positive urine culture

Supportive therapy for both acute epididymitis and orchitis may include:

  • Reduction in physical activity
  • Scrotal support and elevation
  • Use of ice packs
  • Anti-inflammatory agents such as NSAIDs
  • Analgesics, including nerve blocks
  • Avoidance of urethral instrumentation
  • Sitz baths (immersing the scrotum in a tub of warm water)

How can Orchitis and Epididymo-Orchitis be Prevented?

A few preventative measures for Orchitis and Epididymo-Orchitis may include:

  • The mumps-related orchitis can be prevented by MMR vaccine administered during 12-15 months of age, followed by a booster dose at the age of 4-6 years
  • Bacterial epididymo-orchitis can be prevented by proper sexual hygiene and sterile precautions during any transurethral procedures. Also, it is recommended to avoid any strenuous activities when the bladder is full

What is the Prognosis of Orchitis and Epididymo-Orchitis? (Outcomes/Resolutions)

  • The prognosis of Orchitis and Epididymo-Orchitis is generally good with appropriate diagnosis and treatment
  • Pain improves within 1-3 days, but induration may take several weeks or months to resolve. Infection of the epididymis can lead to the formation of an epididymal abscess
  • Patients with sexually transmitted epididymo-orchitis have 2-5 times the risk of acquiring and transmitting an HIV infection

Additional and Relevant Useful Information for Orchitis and Epididymo-Orchitis:

The following DoveMed website link is a useful resource for additional information:


What are some Useful Resources for Additional Information?

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Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: May 27, 2015
Last updated: Dec. 13, 2018