eMedicine Specialties > Urology > Common Problems of the Testicle

Epididymitis

Author: Edmund S Sabanegh Jr, MD, Director, Center for Male Fertility, Glickman Urological and Kidney Institute, Cleveland Clinic Foundation
Coauthor(s): Christina B Ching, MD, Resident, Department of Urology, Cleveland Clinic Foundation; Badrinath R Konety, MD, Associate Professor, Department of Urology, University of California at San Francisco
Contributor Information and Disclosures

Updated: Nov 10, 2009

Introduction

Background

Epididymitis is defined as inflammation of the epididymis, the tightly coiled segment of the spermatic duct that connects the efferent duct from the posterior aspect of each testicle to its respective vas deferens. It is a significant cause of morbidity and is commonly observed by urologists, emergency medicine practitioners, and primary care physicians.

Epididymitis is the fifth most common urologic diagnosis in men aged 18-50 years. It is an important entity to differentiate from testicular torsion, which is a true urologic emergency.

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 induration.

Although epididymitis is thought to be an infectious process, cultures commonly fail to demonstrate any identifiable infection. Infection that is severe and extends to the adjacent testicle is termed acute epididymo-orchitis. Orchitis is an acute inflammatory reaction that involves only the testes, exclusive of epididymitis, and is much less common. Hippocrates first described mumps orchitis during the fifth century BC.

Pathophysiology

The exact pathophysiology of acute epididymitis is unclear; however, it is believed to be caused by the retrograde passage of infected urine from the prostatic urethra to the epididymis via the ejaculatory ducts and vas deferens. Obstruction of the prostate or urethra and congenital anomalies create a predisposition for sterile or urethrovasal reflux. Normally, the oblique angle of the ejaculatory ducts through the dense prostatic tissue prevents reflux. Fifty-six percent of men older than 60 years who have epididymitis exhibit concurrent bladder outlet obstruction (BOO) such as urethral stricture or benign prostatic hyperplasia (BPH).

Reflux may also be induced by Valsalva or strenuous exertion. Epididymitis is commonly found to develop during strenuous exertion in conjunction with a full bladder.

Instrumentation and indwelling catheters are common risk factors for acute epididymitis. Epididymitis may also be accompanied by urethritis or prostatitis. Tuberculous epididymitis may be the presenting feature of genitourinary tuberculosis (TB), which develops via hematogenous spread. Other bloodstream infections may seed the scrotum, especially in children. In a study by Chiang et al, 2 of 7 infants had either Escherichia coli or Neisseria meningitides sepsis associated with epididymo-orchitis.¹

Orchitis is found in association with acute epididymitis in 20%-40% of cases. Orchitis differs from epididymitis in that a viral pathogen (mumps) is an important factor. One third of postpubertal boys diagnosed with mumps develop orchitis.

Frequency

United States

• Epididymitis is the fifth most common urologic diagnosis in men ages 18-50 years. 
• An estimated 1 in 1000 men develop epididymitis annually, and acute epididymitis accounts for more than 600,000 medical visits per year in the United States. 
• The mumps, measles, and rubella (MMR) vaccine has markedly reduced the incidence of mumps orchitis. 
• Chronic epididymitis may account for up to 80% of patients presenting with scrotal pain in the outpatient setting.

Mortality/Morbidity

Complications of acute epididymitis and epididymo-orchitis include the following:

• Scrotal abscess and pyocele
• Testicular infarction
• Chronic epididymitis and orchalgia
• Infertility secondary to inflammation or epididymal duct obstruction
• Testicular atrophy with resulting hypogonadotropic hypogonadism
• Cutaneous fistulization

Race

Epididymitis and orchitis have no predilection for any racial or ethnic group.

Sex

Epididymitis occurs only in males.

Age

• Acute epididymitis most commonly occurs in men aged 20-59 years (43% in men aged 20-39 y and 29% in men aged 40-59 y). Childhood (prepubertal) epididymitis is rare, and testicular torsion is more common in this age group.
• Structural urologic abnormalities are common in children and in men older than 40 years with acute epididymitis. Adults usually have BOO or urethral stricture. Children may have urethral abnormalities such as a prostatic utricle, urethral duplication, posterior urethral valves, or urethrorectal fistula or other anomalies, such as an ectopic ureter, ectopic vas deferens, detrusor sphincter dyssynergia, or vesicoureteral reflux. Siegel et al found that 47% of prepubertal boys with epididymitis had associated urogenital abnormalities, including ectopic vas deferens or ureters, and urethral abnormalities.²
• The average age of a patient with chronic epididymitis is 49 years. Patients often experience symptoms for 5 years before diagnosis.
• Mumps orchitis occurs in 20%-40% of postpubertal boys with the mumps but is rare in prepubertal boys.

Clinical

History

• Acute epididymitis and orchitis
  • Gradual onset of scrotal pain and swelling, often developing over several days (as opposed to hours such as in testicular torsion)
  • Usually located on one side
  • Dysuria, frequency, and/or urgency
  • Fever and chills (in only 25% of adult patients with acute epididymitis but in up to 71% of children with the condition)
  • Usually no nausea or vomiting (as opposed to testicular torsion)
  • Urethral discharge preceding the onset of acute epididymitis (in some cases)
• Chronic epididymitis
  • The patient has a long-standing history of pain (>6 wk) that can be described as either waxing and waning or constant.
  • The scrotum is not usually swollen but may be indurated in long-standing cases.
• Mumps orchitis
  • Fever, malaise, and myalgia are common.
  • Parotiditis typically precedes the onset of orchitis by 3-5 days.
  • Subclinical infections occur in 30%-40% of patients.

Physical

• Acute epididymitis
  • Tenderness and induration first occur in the epididymal tail, which may be the first site of reflux via the vas deferens. It then appears to spread to the body, head, and even the spermatic cord (funiculitis) or the ipsilateral testis (epididymo-orchitis).
  • Prehn sign: In this physical examination, the affected hemiscrotum is elevated. This action relieves the pain of epididymitis but exacerbates the pain of torsion. The elevation takes the weight of the testis off the epididymal suspension.
  • Physical examination findings may fail to distinguish acute epididymitis from testicular torsion. A normal cremasteric reflex indicates that testicular torsion is less likely.
  • Acute epididymitis is bilateral in 5%-10% of affected patients.
  • Erythema and mild scrotal cellulitis may be present.
  • A reactive hydrocele is common in patients with advanced epididymo-orchitis, complicating scrotal examination.
  • Postpubertal individuals with acute epididymitis frequently have associated bacterial prostatitis and/or seminal vesiculitis.
  • TB can cause focal epididymitis, a draining sinus, or beading of the vas deferens with extensive involvement. Orchitis rarely occurs without epididymitis in TB.
  • In children, epididymitis may be related to an underlying congenital anomaly of the urogenital tract, such as urethral abnormalities, an ectopic ureter, an ectopic vas deferens, detrusor sphincter dyssynergia, or vesicoureteral reflux.
• Orchitis
  • Testicular enlargement, induration, and a reactive hydrocele are common.
  • The epididymis is not tender.

Causes

• The etiology of acute epididymo-orchitis varies depending the age of the patient and may involve a bacterial, nonbacterial infectious, noninfectious, or idiopathic process.
  • Nonspecific bacterial infections: Infections with urinary coliforms (eg, E coli, Pseudomonas species, Proteus species, Klebsiella species) are the most common cause in children and in men older than 35 years. Ureaplasma urealyticum, Corynebacterium species, Mycoplasma species, and Mima polymorpha have also been isolated. Systemic Haemophilus influenzae and N meningitides infections are rare. In homosexual men, infections with coliform bacteria are also a common etiology.
  • Sexually transmitted diseases (STDs): Chlamydia is the most common cause in sexually active men younger than 35 years (accounting for up to 50% of cases, although laboratory evidence of chlamydia may be absent in up to 90% of cases). Infections with Neisseria gonorrhoeae, Treponema pallidum, Trichomonas species, and Gardnerella vaginalis also occur in this population.
  • Tuberculous epididymitis: This can occur in endemic areas and is still the most common form of urogenital TB. It is believed to spread hematogenously and often involves the kidneys. Epididymo-orchitis may develop following bacille Calmette-Guérin (BCG) treatment for superficial bladder cancer (at a rate of 0.4%).
  • Viral epididymitis: This is thought to be the predominant etiology of pediatric epididymitis. It is defined by the absence of pyuria. Although mumps is the most common viral cause of epididymitis, coxsackievirus A, varicella, and echoviral infections have also been identified.
  • Other rare infections (eg, brucellosis, coccidioidomycosis, blastomycosis, cytomegalovirus [CMV], candidiasis, CMV in HIV) have been implicated but usually occur in immunocompromised hosts.
  • Roughly 1 in 1000 men who undergo vasectomy describe a postvasectomy pain syndrome of chronic, dull, aching pain in the epididymis and testicle. The pain is most likely secondary to chronic epididymal congestion of sperm and fluid that continues to be produced after the vasectomy. The epididymis can become distended from back pressure of this fluid, particularly following the close-ended vasectomy technique. When sperm extravasates from the end of the vas deferens, such as can occur in the open-ended vasectomy technique, a sperm granuloma may develop with a resulting inflammatory reaction.
  • Obstruction: Men older than 40 years may have BOO (eg, BPH) or a urogenital malformation that predisposes them to urethrovasal reflux and the development of epididymitis; children may have various congenital abnormalities or functional voiding problems that increase the risk of reflux into the ejaculatory ducts.
  • Vasculitic syndromes: Acute epididymitis-orchitis has been described in 12%-19% of individuals with Behçet syndrome. It is also associated with Henoch-Schönlein purpura in the pediatric population, most likely as part of a systemic inflammatory process. Up to 38% of patients with Henoch-Schönlein have scrotal involvement (range, 2%-38%).
  • Amiodarone epididymitis is secondary to high drug concentrations, usually in the head of the epididymis, and can occur in up to 3%-11% of patients taking the drug. This is a dose-dependent phenomenon and typically occurs at dosages greater than 200 mg daily. Epididymal levels of the drug are up to 300 times those of the serum, resulting in anti-amiodarone HCl antibodies that subsequently attack the epididymis, resulting in the symptoms of epididymitis. Histological analysis reveals focal fibrosis and lymphocytic infiltration of epididymal tissues.
  • Sarcoidosis affects the genitourinary system in up to 5% of cases, typically presenting with epididymal nodules.
  • Trauma to the scrotum can be a precipitating event.
  • Some cases are idiopathic.
• Etiology of chronic epididymitis
  • Inadequate treatment of acute epididymitis
  • Recurrent epididymitis
  • Associated with a granulomatous reaction (most commonly Mycobacterium tuberculosis)
  • Associated with a chronic disease process such as Behçet syndrome
• Etiology of acute orchitis
  • Viral: Mumps orchitis was once the most common etiology; however, since the introduction of the mumps vaccine in 1985, this has been virtually eliminated. Roughly one third of postpubertal boys with mumps have concomitant orchitis. Coxsackievirus type A, varicella, and echoviral, adenoviral, enteroviral, influenzal, and parainfluenzal infections are rare.
  • Bacterial and pyogenic infections: Infections with E coli, Klebsiella species, Pseudomonas species, Staphylococcus species, and Streptococcus species are unusual.
  • Granulomatous: T pallidum, M tuberculosis, Mycobacterium leprae, Actinomyces, and fungal diseases are rare.
  • Trauma
  • Idiopathic

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