Epididymitis - Causes

Causes

Though urinary tract infections in men are rare, bacterial infection is the most common cause of acute epididymitis. The bacteria in the urethra back-track through the urinary and reproductive structures to the epididymis. There can be associated urethritis (inflammation of the urethra). In rare circumstances, the infection reaches the epididymis via the bloodstream.

In sexually active men, Chlamydia trachomatis is responsible for two-thirds of acute cases, followed by Neisseria gonorrhoeae and E. coli (or other bacteria that cause urinary tract infection). Particularly among men over age 35 in whom the cause is E. coli, epididymitis is commonly due to urinary tract obstruction. Less common microbes include Ureaplasma, Mycobacterium, and cytomegalovirus, or Cryptococcus in patients with HIV infection. E. coli is more common in boys before puberty, the elderly, and men who have sex with men. In the majority of cases in which bacteria are the cause, only one side of the scrotum or the other is the locus of pain.

Non-infectious causes are also possible. Reflux of sterile urine (urine without bacteria) through the ejaculatory ducts may cause inflammation with obstruction. In children, it may be a response following an infection with enterovirus, adenovirus or Mycoplasma pneumoniae. Rare non-infectious causes of chronic epididymitis include sarcoidosis (more prevalent in black men) and Behçet's disease.

Any form of epididymitis can be caused by genito-urinary surgery, including prostatectomy and urinary catheterization. Congestive epididymitis is a long-term complication of vasectomy. Chemical epididymitis may also result from drugs such as amiodarone.