Epididymitis: Symptoms, Causes, Diagnosis & Treatment

Overview

Epididymitis = inflammation of the epididymis (coiled tube storing/maturing sperm). Acute (<6 wks) vs. chronic (>6 wks). Peak incidence: 19–35 yr (STI-related) and >60 yr (urinary).

Symptoms

Unilateral scrotal pain (gradual onset, worsens over hours–days)
Swelling, erythema, warmth of hemiscrotum
Palpable induration/tenderness of epididymis (posterolateral testis)
Urethral discharge (STI), dysuria, frequency (UTI)
Fever, chills (systemic signs = more severe)
Reactive hydrocele common

Etiology by Age/Risk

Group	Common Pathogens	Mechanism
Sexually active <35 yr	Chlamydia trachomatis, Neisseria gonorrhoeae	Ascending urethritis
MSM	Above + M. genitalium, T. pallidum	Anorectal/oral exposure
>35 yr, urinary abnormalities	Enterobacteriaceae (E. coli, Klebsiella, Proteus), Pseudomonas	Urinary reflux, instrumentation, BPH
Children	E. coli, viral (mumps, adenovirus)	Congenital anomalies, reflux

Diagnosis

Clinical: Prehn's sign (pain relief with scrotal elevation) → supports epididymitis over torsion.
Urinalysis/urine culture: Pyuria, bacteriuria.
NAAT (urine/urethral swab): C. trachomatis, N. gonorrhoeae.
Doppler ultrasound: ↑ epididymal blood flow, size; rules out torsion (↓ flow).

Treatment

Scenario	Regimen (CDC 2021)
Acute, likely STI (gonorrhea/chlamydia)	Ceftriaxone 500 mg IM (1 g if ≥150 kg) + Doxycycline 100 mg BID × 7 days
Enteric organisms (urinary source)	Levofloxacin 500 mg daily × 10 days or Ofloxacin 300 mg BID × 10 days
Chronic/recurrent	Longer course (4–6 wks); consider structural eval (CT urogram, cystoscopy)

Supportive: Scrotal elevation, NSAIDs, ice packs, rest.
Partner treatment for STI etiology (expedited partner therapy).
Surgery: Abscess drainage, epididymectomy (rare, refractory).

Red Flag: Testicular Torsion

Sudden severe pain, high-riding testis, absent cremasteric reflex, no Doppler flow → surgical emergency (detorse within 6 hrs). Do not delay imaging if high suspicion.