Epididymo-orchitis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] :Associate Editor(s)-in-Chief: Abdurahman Khalil, M.D. [2]

Overview

Acute epididymitis is a clinical syndrome consisting of pain, swelling, and inflammation of the epididymis that lasts <6 weeks (402). Chronic epididymitis is characterized by a ≥6 week history of symptoms of discomfort and/or pain in the scrotum, testicle, or epididymis. In most cases of acute epididymitis, the testis is also involved in the process — a condition referred to as epididymo-orchitis. Chronic epididymitis has been subcategorized into inflammatory chronic epididymitis, obstructive chronic epididymitis, and chronic epididymalgia (403). Among sexually active men aged <35 years, acute epididymitis is most frequently caused by C. trachomatis or N. gonorrhoeae. Acute epididymitis caused by sexually transmitted enteric organisms (e.g., Escherichia coli and Pseudomonas spp.) also occurs among men who are the insertive partner during anal intercourse. Sexually transmitted acute epididymitis usually is accompanied by urethritis, which frequently is asymptomatic. In men aged >35 years, sexually transmitted epididymitis is uncommon, whereas bacteriuria secondary to obstructive urinary disease (e.g., benign prostatic hyperplasia) is more common. In this older population, nonsexually transmitted epididymitis is associated with urinary tract instrumentation or surgery, systemic disease, and immunosuppression.

Chronic infectious epididymitis is most frequently seen in conditions associated with granulomatous reaction; Mycobacterium tuberculosis (TB) is the most common granulomatous disease affecting the epididymis. Up to 25% of patients can have bilateral disease, with ultrasound demonstrating an enlarged hyperemic epididymis with multiple cysts and calcifications. Tuberculous epididymitis should be suspected in all patients with a known history of or recent exposure to TB or in patients whose clinical status worsens despite appropriate antibiotic treatment.

Diagnosis

Clinical presentation

• Men who have acute epididymitis typically have unilateral testicular pain and tenderness; hydrocele and palpable swelling of the epididymis usually are present. Although the inflammation and swelling usually begin in the tail of the epididymis, they can spread to involve the rest of the epididymis and testicle.

• The spermatic cord is usually tender and swollen.

• Testicular torsion, a surgical emergency, should be considered in all cases, but it occurs more frequently among adolescents and in men without evidence of inflammation or infection. *Emergency testing for torsion might be indicated when the onset of pain is sudden, pain is severe, or the test results available during the initial examination do not support a diagnosis of urethritis or urinary-tract infection.

• If the diagnosis is questionable, a urologist should be consulted immediately because testicular viability might be compromised

Laboratory tests

• Radionuclide scanning of the scrotum is the most accurate radiologic method of diagnosis, but it is not routinely available.
• Although ultrasound is primarily used for ruling out torsion of the spermatic cord in cases of acute scrotum swelling, it will often demonstrate epididymal hyperemia and swelling in men with epididymitis.
• Differentiation between testicular torsion and epididymitis must be made on the basis of clinical evaluation, because partial spermatic cord torsion can mimic epididymitis on scrotal ultrasound.
• Ultrasound provides minimal utility for men with a clinical presentation consistent with epididymitis; a negative ultrasound does not alter physician management of clinical epididymitis. Ultrasound, therefore, should be reserved for patients with scrotal pain who cannot be diagnosed accurately by physical examination, history, and objective laboratory findings.
• The evaluation of men for epididymitis should include one of the following:

Gram stain of urethral secretions demonstrating ≥5 WBC per oil immersion field. Gram stain is the preferred rapid diagnostic test for evaluating urethritis because it is highly sensitive and specific for documenting both urethritis and the presence or absence of gonococcal infection. Gonococcal infection is established by documenting the presence of WBC containing intracellular Gram-negative diplococci on urethral Gram stain.

• Positive leukocyte esterase test on first-void urine or microscopic examination of first-void urine sediment demonstrating ≥10 WBC per high power field.

• Culture, nucleic acid hybridization tests, and NAATs are available for the detection of both N. gonorrhoeae and C. trachomatis. Culture and nucleic acid hybridization tests require urethral swab specimens, whereas amplification tests can be performed on urine or urethral specimens. Because of their higher sensitivity, amplification tests are preferred for the detection of C. trachomatis. Depending on the risk, patients whose conditions are associated with acquiring an STD should receive testing for other STDs.