Acute inflammation of a testis and epididymis (coiled tube that runs along the back of the testis). Epididymo-orchitis causes acute pain and swelling at the back of the testis, and, in severe cases, swelling and redness of the scrotum. The inflammation is caused by infection. Often, there is no obvious source of the infection, but sometimes the cause is a bacterial urinary tract infection that has spread via the vas deferens (the sperm duct leading to the urethra) to the epididymis. Treatment is with antibiotic drugs. If there is an underlying urinary tract infection, its cause needs to be investigated.
Epididymo-orchitis in more detail - technical
Inflammation confined to the epididymis is epididymitis; infection spreading to the testis is epididymo-orchitis.
Mode of infection
Infection reaches the epididymis via the vas from a primary infection of the urethra, prostate or seminal vesicles. In men with outflow obstruction, epididymitis may result from a secondary urinary infection – a high pressure in the prostatic urethra causes reflux of infected urine up the vasa.
In young men, the most common sexually transmitted infection causing epididymitis is now Chlamydia, but gonococcal epididymitis is still prevalent; both cause urethritis. Blood-borne infections of the epididymis are less common but may be suspected when there is Escherichia coli, streptococcal, staphylococcal or Proteusinfection without evidence of urinary infection.
The initial symptoms are those of urinary infection. Later, an ache in the groin and a fever herald the onset of epididymitis. The epididymis and testis swell and become painful. The scrotal wall, at first red, oedematous and shiny, may become adherent to the epididymis. Resolution may take 6–8 weeks to complete. Occasionally, an abscess may form and discharge of pus may occur through the scrotal skin.
Acute epididymo-orchitis can follow any form of urethral instrumentation. It is particularly common when an indwelling catheter is associated with infection of the prostate. The incidence of acute postoperative epididymitis after prostatectomy has been greatly reduced by closed drainage, catheter care and the early use of antibiotics.
Acute tuberculous epididymitis should be considered when the vas is thickened and there is little response to the usual antibiotics.
Acute epididymo-orchitis develops in about 18% of males suffering from mumps, usually as the parotid swelling is waning. The main complication is testicular atrophy, which may cause infertility if the condition is bilateral (which is not usual). Partial atrophy is associated with persistent testicular pain. Mumps epididymitis sometimes occurs in the absence of parotitis, especially in infants.
The epididymis and testis may be involved by infection with other enteroviruses and in brucellosis and lymphogranuloma venereum.
Doxycycline (100 mg daily) is the treatment of choice for young men with chlamydial infection. If an organism is isolated from the urine, this simplifies the choice of antibiotic. Otherwise, treatment is with an agent that is active against a broad spectrum of urinary tract pathogens. The patient should drink plenty of fluid. Local measures can help to reduce pain. The scrotum is supported on a sling made of broad adhesive tape attached between the thighs. The inflamed organ rests on a pad of cotton wool placed on the sling. Antibiotic treatment should continue for 2 weeks or until the inflammation has subsided.
If suppuration occurs, drainage is necessary. The patient should be warned that the testis may atrophy.
Chronic tuberculous epididymo-orchitis usually begins insidiously.
The frequency with which the lower pole is attacked first indicates that the infection is retrograde from a tuberculous focus in the seminal vesicles.
Typically, there is a firm discrete swelling of the lower pole of the epididymis, which aches a little. The disease progresses until the whole epididymis is firm and craggy behind a normal-feeling testis. There is a lax secondary hydrocele in 30% of cases, and a characteristic beading of the vas may be apparent as a result of subepithelial tubercles. The seminal vesicle feels indurated and swollen. In neglected cases, a tuberculous ‘cold’ abscess forms, which may discharge. The body of the testis may be uninvolved for years but the contralateral epididymis often becomes diseased. In two-thirds of cases there is evidence of renal tuberculosis or previous disease. Otherwise, patients typically appear healthy.
The urine and semen should be examined repeatedly for tubercle bacilli in all patients with chronic epididymo-orchitis. An intravenous urogram and a chest radiograph should be performed.
Secondary tuberculous epididymitis may resolve when the primary focus is treated. Treatment with anti-tuberculous drugs is less effective in genital tuberculosis than in urinary tuberculosis. If resolution does not occur within 2 months, epididymectomy or orchidecto-my is advisable. A course of anti-tuberculous chemotherapy should be completed even if there is no evidence of disease elsewhere.
Chronic non-tuberculous epididymitis usually follows the failure of an acute attack to resolve. The condition is difficult to distinguish from tuberculosis but the swelling may be larger and smoother. It is essential to exclude urethral stricture causing reflux of urine down the vas. If alternative granulomatous conditions such as sarcoidosis have been eliminated, chronic epididymitis should be treated with antibiotics. Epididymectomy or orchidectomy should be considered if there is no resolution after 4–6 weeks of conservative treatment.