What Is Epididymitis (Testicle Infection)?
Picture of the male urinary and reproductive system.
Epididymitis is infection or less frequently, inflammation of the epididymis (the coiled tube on the back of the testicle). The majority of men that develop epididymitis develop it because of a bacterial infection. Although males of any age can develop epididymitis, it occurs most frequently between ages of 20 to 39. When it develops in children, it is usually due to inflammation caused by trauma. However, some children develop it because of bacterial infections, some of which may be due to sexual abuse. In general, individuals have discomfort and pain in the area of the testicle(s) or groin; some may develop fever, penile discharge, and blood in the urine.
The epididymis is a firm tube that lies on the back surface of each testicle. It is coiled in order to fit a length of nearly 20 feet into a small space. This long length acts as a storage space for the sperm and gives sperm time to mature. The epididymis can be divided into three sections: 1) the head (an expanded upper end), 2) the body, and 3) the pointed tail.
The epididymis also absorbs fluid and adds substances to help nourish the maturing sperm. Each epididymis is directly attached to the testicle so that if the epididymis becomes infected or develops inflammation, the testicle may also develop infection or inflammation. This is termed epididymo-orchitis (infection/inflammation of both the epididymis and testicle). Also, testicular infection is the most common reason for inflammation in the scrotum. The other end of the epididymis attaches to the vas deferens which leads to the prostate gland and then to the urethra. Infections and inflammation often proceed retrograde (also termed backflow) from the urethra; rarely is infection/inflammation spread through the blood to the epididymis.
What Are the Symptoms of Epididymitis?
Symptoms of epididymitis start gradually and often peak within 24 hours. Pain usually begins in the scrotum or groin.
- Abdominal or flank pain: At first, inflammation begins in the vas deferens (which is the duct that carries sperm to the urethra) and then descends to the epididymis. This descent explains why symptoms can start initially in the flank (lower back) and groin. One side of the groin or testicle may be much more painful than the other.
- Scrotal pain and swelling: The epididymis may swell to twice normal size within 3-4 hours (the degree of swelling is variable).
- Pain on urination, occasionally blood in the urine.
- Discharge from the urethra (at the end of the penis; especially in men younger than 39 years of age)
- Fever and chills
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What Causes Epididymitis?
The cause of epididymitis is usually a bacterial infection. The bacteria usually get to the epididymis by moving back through (retrograde) the urethra, prostate, vas deferens into the epididymis. The responsible bacteria are usually identified in about 80% of cases.
Two main groups of organisms cause most cases of epididymitis: sexually transmitted organisms and coliforms (organisms that commonly live in the intestines).
- In men younger than about 39 years of age, the causes are usually the same organisms that cause the sexually transmitted diseases of chlamydia (responsible for nearly 50%-60% of cases) and gonorrhea. The bacterial species are Chlamydia trachomatis and Neisseria gonorrhea, respectively.
- In those older than 39 years of age, the causes are usually coliforms, which are bacteria (such as Escherichia coli) that live in the intestines. These organisms also frequently cause bladder infections. Any age of men who participate in anal intercourse are more likely to get infected with E. coli or other fecal bacteria. Epididymitis is rarely caused by fungi or Mycobacterium spp.
- Chemical epididymitis (rare) is inflammation caused by the retrograde (backward) flow of urine when exercising or having sex with a full bladder.
- Amiodarone (Nexterone), a frequently used heart medication, occasionally causes inflammation of the epididymis.
- Viral infections (including mumps), mainly in the pediatric population.
When to Seek Medical Care
Mild scrotal pain, urinary symptoms, or any of the other symptoms of epididymitis listed above merit a visit to a health care practitioner because the treatment for epididymitis involves prescription antibiotics. If the doctor is concerned about complications or an alternative diagnosis, the individual will likely be sent to a hospital for further tests. If a boy or man has scrotal pain or urinary symptoms and cannot be seen soon by a health care practitioner, he should go to a hospital's emergency department. Symptoms that require urgent care include the following:
Severe scrotal pain: This could represent testicular torsion, which is a very serious disease that needs immediate attention. The outcome for this particular diagnosis is time dependent. The faster the man receives treatment, the less damage may be done since torsion limits or cuts off blood flow to the testicle. Seek care immediately.
Urinary symptoms such as:
- discharge from the penis,
- pain or burning with urination, and
- urinary frequency (more often than normal).
- Fever and chills
- Abdominal or flank pain
- Lumps or swelling in the testicles; one testicle increasing in size
These symptoms may indicate an epididymitis infection, but a health care practitioner needs to examine the individual to help determine the diagnosis and determine if an emergency condition exists (for example, testicular torsion or necrotizing fasciitis).
How Is Epididymitis Diagnosed?
A health care practitioner will take a detailed history (including a sexual history), collect a urine sample, and perform a physical examination, including a prostate exam.
- Urinalysis and urine culture: These tests aid in the diagnosis of a urinary tract infection (bladder infection).
- Urethral culture
- Urine can be tested for sexually transmitted diseases present in the urethra.
- Sometimes a swab is inserted about one-half inch into the urethra and sent for testing (although uncomfortable, it only takes a few seconds).
- The results usually take about a day to come back to the health care practitioner, so follow-up is very important.
- The health care practitioner often also orders other tests such as a white blood cell count. A white blood cell count may be high if infection is present. A Gram-stain of urethral exudates, in some cases, can presumptively diagnose the infecting bacteria.
- There are several rapid tests for some of the bacteria that cause epididymitis (N. gonorrhea, C. trachomatis). They detect the organisms by PCR and immunological methods. However, these tests usually require confirmation by actually culturing the bacteria.
- Ultrasound and nuclear scans help differentiate testicular torsion from epididymitis.
- CT and MRI scans are used occasionally to help determine and differentiate between many conditions that can cause some symptoms similar to epididymitis (for example, cysts, hydrocele formation (fluid filled area), hernias, cancerous tissue, or the extent of abscesses or gangrene in swollen testicles).
The correct diagnosis of the cause of epididymitis by health care practitioners is important because an incorrect diagnosis may lead to many problems beyond the symptoms in the individual. The majority of infections involving the epididymis (over 50%) are due to sexually transmitted infectious agents or by bacteria acquired during sexual intercourse. Consequently, sexual partners of many patients should be notified and treated, even if they currently show no symptoms. However, many men (usually older than 39 years of age) and some children can acquire the disease without it being linked to sexual transmission (for example, bladder infection or chemical inflammation). Consequently, health care practitioners need to take a detailed history from the patient, and the patient has the responsibility to answer medical history questions honestly. The situation is even more complex when children have symptoms of epididymitis; most experts suggest that a Child Protective Agency be contacted if sexual abuse is suspected.
What Is the Treatment for Epididymitis?
The health care practitioner likely will treat the individual with antibiotics through an IV, a shot, or pills orally (to be taken for 10 days or longer). Often the treatment depends on the identity of the infecting bacteria; many physicians elect to treat with at least two different antibiotics because individuals are occasionally infected with more than one organism.
In men younger than 39 years of age:
In men older than 39 years of age or those who participate in anal intercourse (and do not have an STD caused by N. gonorrhoea or C. trachomatis):
The CDC guidelines recommend that for acute epididymitis most likely caused by enteric organisms or with negative gonococcal culture or PCR nucleic acid amplification test, treat with the following:
Guidelines change frequently; most health care practitioners who treat epididymitis are aware of these guidelines, and depending on local resistance patterns of pathogens, may change the type and duration of antibiotics to best fit the patient's condition. Pediatric treatments are best administered by pediatricians and are usually based on the weight of the patient and the infecting organism's antibiotic susceptibility. If the infection is not treated early, complications may develop that require surgery.
For patients with non-infectious causes of epididymitis (for example, chemical, inflammation) anti-inflammatory medication is often prescribed; occasionally, consultation with a urologist is recommended for additional treatments.
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Do I Need to Follow up with My Doctor after Treatment?
Follow-up with your health care practitioner to ensure the antibiotics are working.
- If the individual does not respond to antibiotics, he may need an ultrasound (ordered by the doctor or urologist, who is a specialist in genital conditions).
- It is important to be sure that the condition doesn't progress to become orchitis, an infection of one or both testicles. Orchitis also can result from the spread of bacteria through the blood from other locations in the body. This is called epididymo-orchitis if the epididymitis is also infected.
- Less commonly, a testicular tumor may be present. An ultrasound or blood test might be needed if tumor is suspected.
- If epididymitis occurred because of sexual transmission of infectious bacteria, all sex partners of the man should be notified and treated even if they have no current symptoms.
How Can You Prevent Epididymitis?
For men younger than 39 years of age, the cause is usually a sexually related disease. If one partner is infected, the other partner should be evaluated and potentially treated as well. Otherwise, the patient may become reinfected. Other prevention methods are as follows:
- abstinence (no sexual relations);
- condom use (reduces chances for infection by about 90%);
- monogamy with only one uninfected sex partner;
- preventing child abuse in pediatric patients; and
- mumps vaccination.
Those individuals that develop epididymitis secondary to taking amiodarone medication will likely need a different medication if they must stop the drug. Consultation, usually with a cardiologist, is recommended to switch to another drug.
For men older than 39 years of age, good hygiene is suggested for those who are uncircumcised to help prevent urethral and bladder infections.
What Is the Outlook for Epididymitis?
If treated appropriately with antibiotics, epididymitis should be cured and the individual will have an excellent prognosis (outlook).
The pain should improve within 1-3 days; however, swelling may take several days to resolve.
However, complications are possible, including:
- Sterility: If the epididymitis involves both sides and is untreated, sterility may result (rarely, sterility can still occur even with antibiotic treatment).
- Scrotal abscess (an infection)
- Co-infection of the testicle (epididymo-orchitis)
- Sepsis (spread of infection into the bloodstream)
- Fournier gangrene (a severe and life-threatening infection of the scrotal area that kills the cells)
The longer treatment is delayed, the more likely the above complications may develop and thus reduce the individual's outcome to only fair to poor, depending on the severity of the complications.
Reviewed on 10/14/2019
CDC. "Gonococcal Infections; Sexually Transmitted Diseases Treatment Guideliens, 2010." Updated: Jan 28, 2011.
Ching, CB. "Epididymitis." Medscape. Updated: Dec 09, 2016.