Epididymitis
Epididymitis is inflammation of the epididymis, most often infectious, causing unilateral scrotal pain and swelling of gradual onset that must be distinguished urgently from testicular torsion. Diagnosis is clinical, supported by a positive Prehn sign and preserved cremasteric reflex, and treatment is empiric ceftriaxone plus doxycycline for age under 35 or STI risk, or levofloxacin alone for age over 35 with enteric-organism risk.
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What this article covers
- Overview
Epididymitis is inflammation of the epididymis, usually caused by infection, producing unilateral scrotal pain and swelling that develops gradually and worsens over days.
- Epidemiology
Sexually transmitted epididymitis in men under 35 years is usually accompanied by asymptomatic urethritis and an absence of bacteriuria, reflecting its origin as an ascending genital tract infection.
- Risk factors
Sexual activity in men younger than 35 years, the dominant risk factor for chlamydia- and gonorrhea-associated epididymitis.
- Pathophysiology
Infection typically ascends from the urethra through the vas deferens into the epididymis, producing local inflammation, edema, and pain.
- Clinical features
Unilateral scrotal pain and swelling of gradual onset that worsens over a period of days is the hallmark presentation, distinguishing epididymitis from the acute, rapidly progressive pain of testicular torsion.
- Differential diagnosis
Testicular torsion: acute, severe pain progressing rapidly over hours (not days), an elevated and transversely oriented testis, absent cremasteric reflex, and a negative Prehn sign; a surgical emergency requiring immediate exploration.
- Diagnosis
Epididymitis is primarily a clinical diagnosis, established by unilateral scrotal pain and swelling of gradual onset together with a positive Prehn sign and an intact cremasteric reflex, without the…
- Management
First, exclude testicular torsion clinically; if torsion is suspected (acute severe pain over hours, elevated testis, absent cremasteric reflex, negative Prehn sign), proceed directly to emergent…
- Complications
Testicular infarction from missed concurrent or evolving torsion, the most serious risk of a missed or delayed diagnosis, underscoring the priority of excluding torsion first.
- Prognosis
Most cases of acute epididymitis resolve fully with appropriate empiric antibiotics and supportive care, typically within 1-2 weeks of starting therapy.
- Prevention
Use condoms consistently during sexual activity to reduce risk of chlamydial and gonococcal infection, the leading cause of epididymitis in men under 35 years.
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Related articles
- Testicular torsion
Testicular torsion is twisting of the spermatic cord causing testicular ischemia, presenting with acute severe unilateral scrotal pain, a swollen high-riding testis in a horizontal lie, and an absent cremasteric reflex; it is a surgical emergency diagnosed clinically without delaying for imaging, and testicular viability falls from 90-100% within 6 hours of symptom onset to under 10% beyond 24 hours, so immediate surgical exploration with detorsion and bilateral orchiopexy is the definitive treatment.
- Orchitis
Orchitis is inflammation of the testis, most commonly viral (mumps) with isolated testicular involvement or bacterial as a contiguous extension of epididymitis (epididymo-orchitis), presenting as testicular pain and swelling that must be distinguished from the surgical emergency of testicular torsion. Diagnosis is clinical, guided by exposure history and preserved cremasteric reflex, with mumps orchitis managed supportively and bacterial epididymo-orchitis treated with the same age- and risk-stratified antibiotics used for epididymitis.
- Hydrocele
Hydrocele is a painless accumulation of serous fluid within the tunica vaginalis, congenital and communicating in infants or acquired and noncommunicating in adults, diagnosed by transillumination and confirmed with scrotal ultrasound; treatment is observation for asymptomatic disease and hydrocelectomy for persistent or symptomatic cases.
- Varicocele
Varicocele is dilation of the pampiniform venous plexus and internal spermatic veins, usually left-sided because of the right-angle insertion of the left gonadal vein into the left renal vein, presenting as a painless, non-transilluminating 'bag of worms' scrotal mass that augments with standing or Valsalva and is a leading cause of male infertility. Diagnosis is clinical, confirmed by scrotal Doppler ultrasound when uncertain, and management is conservative (scrotal support, NSAIDs) for asymptomatic cases without testicular atrophy, escalating to surgical ligation or percutaneous embolization for pain, testicular atrophy, or infertility in a patient desiring fertility.
- Acute prostatitis
Acute bacterial prostatitis is a sudden bacterial infection of the prostate presenting with local urinary symptoms plus fever, chills, and a tender boggy prostate on exam. Diagnosis is clinical, confirmed by urinalysis and culture, and treatment is empiric antibiotics chosen by patient age and risk, continued for 2-4 weeks.
- Chlamydia trachomatis infection
Chlamydia trachomatis is the most commonly reported bacterial sexually transmitted infection in the United States, frequently asymptomatic, and diagnosed by nucleic acid amplification testing of urine or genital/rectal/oropharyngeal swabs. Uncomplicated genital infection is treated with a single dose of azithromycin or a course of doxycycline, complications include pelvic inflammatory disease and epididymitis, and LGV serovars require a 21-day course and are an increasing cause of proctitis.
- Neisseria gonorrhoeae gonococcal infection
Neisseria gonorrhoeae is a gram-negative intracellular diplococcus that infects columnar and transitional epithelium of the cervix, urethra, rectum, pharynx, and conjunctiva, and disseminates hematogenously in 1% to 3% of infections to cause the arthritis-dermatitis syndrome or purulent monoarthritis; treatment is ceftriaxone-based because cephalosporin resistance is emerging and fluoroquinolones are no longer reliable.
- Infectious urethritis
Infectious urethritis is inflammation of the urethra from a sexually transmitted pathogen, most often Neisseria gonorrhoeae, Chlamydia trachomatis, or Mycoplasma genitalium, presenting with dysuria and urethral discharge. Diagnosis rests on urethral or urine leukocytes plus nucleic acid amplification testing, and empiric treatment covers gonorrhea with ceftriaxone and chlamydia with doxycycline while results are pending.