AKT · Renal & urology/Scrotum & male GU

Prostatitis, epididymitis & orchitis

Infection/inflammation of the prostate / epididymis / testis — STI (young) or coliforms (older)

Overview

Infection or inflammation of the prostate (prostatitis), epididymis (epididymitis) or testis (orchitis). The crucial split is the likely organism by age/risk: sexually transmitted (Chlamydia, gonorrhoea) in younger sexually active men vs enteric coliforms (E. coli) in older men/those with urinary tract issues — because it changes the antibiotic. Epididymo-orchitis is the main mimic of testicular torsion.

Recognise

Epididymo-orchitis: GRADUAL onset of scrotal pain/swelling, tender epididymis/testis, fever, dysuria/discharge; positive Prehn's sign (pain eased by elevation), present cremasteric reflex
Prostatitis: pelvic/perineal pain, LUTS, painful ejaculation, fever (acute); a tender/boggy prostate on DRE (avoid vigorous massage in acute prostatitis)
Orchitis: testicular inflammation — mumps orchitis (post-pubertal, often with parotitis); viral causes

Red flags

Cannot reliably exclude TORSION → if any doubt (especially sudden onset in a young man), explore surgically — torsion is the can't-miss
Acute bacterial prostatitis with sepsis or a prostatic abscess → admit/IV antibiotics ± drainage; urinary retention

Differentials & how to tell them apart

Testicular torsionSUDDEN severe pain, high-riding testis, absent cremasteric reflex, negative Prehn's — explore if in doubt

Testicular tumourpainless hard mass — ultrasound

Mumps orchitisviral, often bilateral parotitis, post-pubertal — supportive, no antibiotics

Investigations

Urine dip + MSU; first-void urine NAAT for chlamydia/gonorrhoea (younger/sexually active); bloods/cultures if septic; scrotal ultrasound if abscess or torsion uncertain (but don't delay exploration if torsion possible); DRE for prostatitis.

Management

Antibiotics by likely organism — STI (ceftriaxone+doxycycline) vs enteric (quinolone); exclude torsion first

1First EXCLUDE torsion (sudden onset/young → explore if any doubt). For epididymo-orchitis, treat by likely organism: STI cover (ceftriaxone + doxycycline) in younger sexually active men, enteric cover (a quinolone) in older men.Gate: The age/risk determines the antibiotic — and torsion is the can't-miss: don't anchor on 'infection' in a young man with sudden severe pain.
2Acute prostatitis → a prolonged quinolone course (drain an abscess, admit if septic); mumps orchitis → supportive care; treat/notify partners for STI causes (cross-ref sexual_health).

Epididymo-orchitis — STI likely (younger): ceftriaxone + doxycycline — cover gonorrhoea + chlamydia; treat/notify partners (cross-ref sexual_health)

Epididymo-orchitis — enteric likely (older/low STI risk): a quinolone (e.g. ofloxacin/ciprofloxacin) or other per local guidance — covers coliforms; consider underlying urinary obstruction

Acute bacterial prostatitis: prolonged antibiotics (e.g. ciprofloxacin/ofloxacin, 2–4 weeks) — good prostate penetration; drainage if abscess; admit if septic

Mumps orchitis: supportive (analgesia, rest) — viral — no antibiotics; MMR prevention

Key points

Epididymo-orchitis = GRADUAL pain, fever, positive Prehn's (elevation helps), present cremasteric reflex — vs torsion (sudden, high-riding, absent reflex, negative Prehn's): explore if in doubt. Antibiotic by AGE/RISK: STI (ceftriaxone + doxycycline) in young men, enteric coliform (quinolone) in older men. Prostatitis → prolonged quinolone.

Monitor & prognosis

Symptom resolution, cultures/NAAT, partner treatment; exclude underlying obstruction.

Good with appropriate antibiotics; chronic prostatitis can be relapsing.

Source: NICE CKS; BASHH; cross-ref sexual_health, child_health (mumps)