Epididymitis

Overview

Epididymitis is inflammation of the epididymis, the coiled tube located behind each testicle that stores and transports sperm. This condition typically causes pain, swelling, and tenderness in the scrotum, usually affecting one side. When infection spreads to involve the testicle itself, the condition is called epididymo-orchitis.

The epididymis measures approximately 6 meters when uncoiled and sits on top of and behind each testicle. It connects the testicle to the vas deferens and stores sperm as they mature. Epididymitis affects approximately 600,000 men annually in the United States and represents the most common cause of scrotal pain in adult men. Incidence peaks in men aged 18 to 35, primarily due to sexually transmitted infections, with a second peak in men over 55, typically from urinary tract bacteria.

Acute epididymitis refers to symptoms present for less than six weeks, while chronic epididymitis describes persistent symptoms lasting longer. Most cases respond well to antibiotic treatment, though the condition can become frustrating to manage if it progresses to a chronic state.

Symptoms

Scrotal pain develops gradually over hours to days, distinguishing epididymitis from testicular torsion, which causes sudden severe pain. The pain typically affects one side and may radiate to the groin or lower abdomen. Physical activity worsens discomfort, while elevating the scrotum often provides relief.

The affected side of the scrotum appears swollen and may feel warm to the touch. The epididymis itself becomes thickened and exquisitely tender. Redness of the scrotal skin develops as inflammation progresses, and fluid may collect around the testicle, forming a hydrocele.

Many men with epididymitis experience urinary symptoms including burning with urination (dysuria), urinary frequency, and urethral discharge. Blood in the urine occasionally occurs. Systemic symptoms such as fever, malaise, and nausea indicate more significant infection.

Causes

In sexually active men under age 35, sexually transmitted organisms cause most cases. Chlamydia trachomatis is the most common STI cause, followed by Neisseria gonorrhoeae. These infections often coexist, and urethritis frequently accompanies or precedes epididymitis in these cases.

In older men and those with urinary tract abnormalities, bacteria from the urinary system cause most infections. Escherichia coli is the predominant organism, though Klebsiella, Pseudomonas, and other Enterobacteriaceae also occur. These cases often develop in the setting of urinary tract infection, bladder outlet obstruction from benign prostatic hyperplasia, or recent urological procedures such as catheterization or cystoscopy.

Less common causes include reflux of sterile urine causing chemical inflammation, the heart medication amiodarone, tuberculosis in endemic regions, and viral infections such as mumps. Men who have sex with men may develop epididymitis from either STI organisms or enteric bacteria.

Diagnosis

Accurate diagnosis requires distinguishing epididymitis from testicular torsion, a surgical emergency requiring intervention within six hours to save the testicle. Torsion typically causes sudden-onset severe pain in adolescents, while epididymitis develops gradually and more commonly affects men in their twenties or older. Urinary symptoms and fever suggest epididymitis, whereas their absence raises concern for torsion.

Physical examination reveals a tender, swollen epididymis with the testicle in its normal position. The cremasteric reflex remains intact in epididymitis but is typically absent in torsion. Pain that improves with scrotal elevation, known as Prehn’s sign, suggests epididymitis rather than torsion.

Urinalysis often shows white blood cells and bacteria. Nucleic acid amplification testing on a first-void urine sample or urethral swab detects chlamydia and gonorrhea. Urine culture identifies bacterial causes and guides antibiotic selection, particularly important in older men. Scrotal ultrasound with Doppler demonstrates increased blood flow to the epididymis and rules out torsion by confirming preserved testicular blood flow. When torsion cannot be excluded clinically, urgent ultrasound or surgical exploration is mandatory.

Treatment

Antibiotic therapy begins empirically before test results return. For sexually active men under 35 where STI is suspected, treatment consists of a single intramuscular dose of ceftriaxone 500mg to cover gonorrhea plus doxycycline 100mg twice daily for 10 to 14 days to cover chlamydia. Men who have sex with men should receive coverage for both STI organisms and enteric bacteria.

For older men or those with suspected urinary tract source, fluoroquinolones such as levofloxacin 500mg daily or ofloxacin 300mg twice daily for 10 to 14 days provide appropriate coverage. Treatment may be adjusted once culture results identify the specific organism and its antibiotic sensitivities.

Supportive measures reduce discomfort during recovery. Nonsteroidal anti-inflammatory medications such as ibuprofen or naproxen control pain and inflammation. Ice packs applied for 15 to 20 minutes at a time, wrapped in cloth to protect the skin, provide additional relief. Scrotal support or elevation helps reduce swelling. Rest during the acute phase is important, and men should avoid heavy lifting and sexual activity until treatment is complete and symptoms resolve.

When STI causes epididymitis, all sexual partners from the preceding 60 days require testing and treatment. Men should abstain from sexual activity until they and their partners complete treatment and symptoms resolve. Condom use is essential when resuming sexual activity.

When to See a Doctor

Sudden-onset severe testicular pain requires immediate medical evaluation to exclude testicular torsion. Any man with scrotal pain, swelling, or redness should seek prompt medical attention, as early treatment of epididymitis prevents complications.

Return for urgent evaluation if symptoms worsen despite antibiotics, high fever develops, severe swelling occurs, redness spreads across the scrotal skin, or systemic illness develops. These signs may indicate abscess formation or spreading infection requiring more aggressive treatment.

Follow up if symptoms do not improve after three days of antibiotic therapy or if symptoms return after treatment. Men with STI-related epididymitis should return for test of cure to confirm infection clearance. Untreated or inadequately treated epididymitis can lead to abscess formation requiring drainage, chronic pain syndromes, and in cases affecting both sides, potential fertility impairment.

Chronic epididymitis, defined as symptoms persisting beyond six weeks, may develop even after appropriate initial treatment. This frustrating condition often shows no active infection and may require extended management including anti-inflammatory medications, physical therapy, nerve blocks, or rarely surgical intervention.