Etiology
Acute epididymitis is commonly observed in young and middle-aged men. It often results from the spread of infections in the urinary tract, prostatitis, seminal vesiculitis, or sexually transmitted diseases. The infection typically spreads retrogradely via the vas deferens, with hematogenous spread being rare. The primary causative pathogens include Escherichia coli, but Neisseria gonorrhoeae, Chlamydia trachomatis, and viruses can also be responsible. In older men, following open prostatectomy or transurethral resection of the prostate, the ejaculatory duct may open into the prostatic fossa. Increased pressure during urination can lead to retrograde flow of bacteriuria into the epididymis through the vas deferens. In cases where sterile urine flows retrogradely into the epididymis, chemical epididymitis may develop. Rarely, the condition may be caused by an ectopic ureteral opening.
Pathology
Inflammation leads to swelling of the epididymis, typically beginning in the tail of the epididymis and then spreading through the body to the head. Abscess formation may occur. When the testis is involved, epididymo-orchitis develops. Hydrocele may result from effusion into the tunica vaginalis, while the spermatic cord may thicken. Inflammatory reactions can extend to the inguinal region.
Clinical Manifestations
The onset is sudden and often secondary to infections of the lower urinary tract. Systemic symptoms such as chills and high fever are prominent. On the affected side, significant scrotal swelling is observed. The scrotal skin may appear red, warm, and painful, with pain radiating along the spermatic cord, lower abdomen, and perineum. Enlargement or thickening of the epididymis, testes, and spermatic cord is usually present, with the swelling being most pronounced in the head or tail of the epididymis. At times, the boundaries between the epididymis and testes become indistinct, with pain intensifying when the affected side hangs downward. Bladder irritative symptoms may also be present. Laboratory findings show elevated white blood cell count and neutrophilia.
Diagnosis
Diagnosis is straightforward based on the characteristic clinical presentation. Localized tenderness of the epididymis is typically noted during physical examination. Differentiation from other scrotal conditions such as testicular torsion is necessary. Testicular torsion most often affects adolescents, with abrupt onset during periods of inactivity, severe scrotal pain, and marked swelling and tenderness of the epididymis and testes. Ultrasound is useful for differential diagnosis, as it reveals increased blood flow in acute epididymitis, whereas testicular torsion is characterized by ischemia and decreased blood flow.
Treatment
Rest in bed is recommended with elevation of the scrotum as needed for support. Pain relief can be achieved with analgesics and warm compresses. A spermatic cord block with 0.5% lidocaine may be utilized to alleviate pain. Broad-spectrum antibiotics are typically selected for treatment. Severe cases are managed with early intravenous antibiotic therapy. Drainage may be necessary if abscess formation occurs.