Acute epididymitis is inflammation of the epididymis causing pain and swelling that develops over the course of a few days and lasts <6 weeks. It is usually unilateral.
In sexually active men, epididymitis is most commonly caused by sexually transmitted organisms including Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium.
In older men, the causative organisms are often enteric pathogens, and epididymitis may be associated with bladder outlet obstruction, recent instrumentation of the urinary tract, or systemic illness.
Diagnostic tests include a Gram stain of urethral secretions, and urine specimens for nucleic acid amplification tests for C trachomatis, N gonorrhoeae, and M genitalium (where available). Urine microscopy and culture is also indicated if urinary pathogens are suspected.
Treatment relies on supportive measures, including bed rest, scrotal elevation, and analgesics, in conjunction with empiric antibiotic therapy based on the patient's age, and clinical and sexual history. Once diagnostic test results are available, antibiotics can be adjusted to target the causative organism(s).
If C trachomatis, N gonorrhoeae, or M genitalium are the confirmed or suspected pathogens, evaluation and treatment of the patients’ sexual partner(s) is essential to prevent reinfection and ongoing transmission.
Acute epididymitis is inflammation of the epididymis characterized by scrotal pain and swelling of less than 6 weeks' duration. It may be associated with irritative lower urinary tract symptoms, urethral discharge, and fever. It is usually unilateral. The condition is referred to as acute epididymo-orchitis if concurrent inflammation of the testis is present. The acute presentation of epididymitis will be covered.
History and exam
Key diagnostic factors
- age >19 years
- unilateral scrotal pain and swelling of gradual onset
- symptoms <6 weeks' duration
- hot, erythematous, swollen hemiscrotum
- frequent and painful micturition
- purulent urethral discharge
Other diagnostic factors
- fluctuant swelling or induration of scrotal tissue
- enlarged or tender prostate
- unprotected sexual intercourse
- bladder outflow obstruction
- instrumentation of urinary tract
- exposure to tuberculosis (TB)
1st investigations to order
- Gram stain of urethral secretions
- urine dipstick test
- urine microscopy
- urine culture
- nucleic acid amplification test (NAAT) of urethral secretions or first-void urine for Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium
- culture of urethral secretions
Investigations to consider
- scrotal color duplex ultrasonography
- surgical exploration
- 3 early morning urine samples for acid-fast bacilli staining, culture, and NAAT for Mycobacterium tuberculosis
- HIV test
- syphilis test
idiopathic or viral
- Testicular torsion
- Acute idiopathic scrotal edema
- Infected hydrocele
- ACR appropriateness criteria: acute onset of scrotal pain - without trauma, without antecedent mass
- 2021 European guideline on Mycoplasma genitalium infections
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