History and exam
Key diagnostic factors
common
age >19 years
Epididymitis is a common cause of acute scrotal pain in adolescent and adult males.[7]
unilateral scrotal pain and swelling of gradual onset
Pain and swelling typically develops over the course of a few days (unlike testicular torsion, which is usually of sudden onset).
symptoms <6 weeks' duration
Symptoms over 6 weeks' duration indicate chronic inflammation.
tenderness
The epididymis can be felt as a tubular structure that lies posterior to the testis and runs in a sagittal plane. It is tender in case of epididymitis.
hot, erythematous, swollen hemiscrotum
Diffuse enlargement of the testis will be present in epididymo-orchitis.
uncommon
frequent and painful micturition
Common feature of lower urinary tract infection.
purulent urethral discharge
Suggests sexually transmitted infection.
Other diagnostic factors
uncommon
pyrexia
Systemic symptoms are more suggestive of an infectious cause.
fluctuant swelling or induration of scrotal tissue
May represent a reactive hydrocele or abscess formation.
enlarged or tender prostate
A digital rectal examination is recommended to assess for benign prostatic enlargement, which may suggest underlying bladder outflow obstruction and increased risk of acute epididymitis, and exclude tenderness of the prostate suggestive of concurrent acute prostatitis.
Risk factors
strong
unprotected sexual intercourse
In sexually active men of all ages, acute epididymitis is most commonly caused by sexually transmitted pathogens such as Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium.[15]
Men who have sex with men are at risk of acute epididymitis caused by the transmission of enteric pathogens such as Escherichia coli during unprotected insertive anal intercourse.[15]
bladder outflow obstruction
In older men, obstructive urinary symptoms secondary to bladder neck obstruction, benign prostatic hyperplasia, or urethral stricture are associated with an increased risk of acute epididymitis.[1][23]
Incomplete bladder emptying and higher voiding pressures lead to reflux of infected urine into the ductal system and spread of pathogens to the epididymis.
instrumentation of urinary tract
Cystoscopic procedures and urethral catheterization (intermittent and indwelling) increase the risk of lower urinary tract infection.[12][24] Pathogens are then able to spread to the epididymis via the ejaculatory ducts and vas deferens.
It is important to remember that patients undergoing these procedures are also more likely to have other underlying risk factors, such as bladder outflow obstruction.
weak
immunosuppression
Atypical organisms are more likely to be associated with immunosuppression from a variety of causes, including transplant recipients, HIV, and diabetes.[20]
Epididymitis caused by Candida albicans, Haemophilus influenzae, Mycobacterium tuberculosis, and cytomegalovirus are more often seen in patients with HIV, while diabetes may predispose to infections caused by Candida sp.and nocardiosis.[20]
vasculitis
Most commonly Behçet syndrome and Henoch-Schönlein purpura.
amiodarone
Rare, but the most common drug-induced cause.
mumps
Viral epididymitis is rare in the adult population, but an increase of mumps epididymitis has been seen in the UK due to the 2005 mumps epidemic in a cohort of nonimmunized adults.[3]
exposure to tuberculosis (TB)
Rare cause. The epididymis is a common site of hematogenous implantation of the TB bacilli following primary pulmonary infection and may remain latent for decades.[17] A history of prior TB, exposure to a patient with TB, or travel to a TB endemic region may be (but is not always) present.[17] Tuberculous epididymo-orchitis is also a rare complication of intravesical BCG therapy for bladder cancer.[17][19]
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