Infectious DiseasesTier 2Disease (DEADMAN)

Genito-urinary conditions - epididymo-orchitis

Description

Epididymo-orchitis is inflammation of the epididymis (and, if extending, the testis) - in sexually active younger men most often caused by STI pathogens (chlamydia, gonorrhoea), while in older men or those with recent urinary instrumentation it more often reflects urinary pathogen ascent (E. coli and other Gram-negative organisms)

Epidemiology

A common cause of acute scrotal pain in adult men, with age and sexual history shaping the likely causative organism and therefore empirical antibiotic choice

Aetiopathogenesis

Infection typically ascends from the urethra (STI pathogens) or bladder (urinary pathogens) along the vas deferens to the epididymis - the age/risk-factor-dependent organism difference reflects these two distinct ascending routes

Diagnosis

Testicular torsion is the critical differential and must be excluded first in any acute scrotal pain presentation, given the time-critical nature of torsion (testicular viability falls sharply beyond 6 hours) - see for the full approach to this presentation
Urine NAAT for chlamydia/gonorrhoea and midstream urine culture guide organism-directed treatment once torsion is excluded

Management

Empirical antibiotic choice is guided by likely organism: STI-directed cover (e.g. ceftriaxone plus doxycycline) in younger sexually active men, urinary pathogen-directed cover (e.g. fluoroquinolone) in older men/those with recent instrumentation
Partner notification and STI screening apply when an STI organism is identified or strongly suspected

Associations

Testicular torsion (the critical, time-sensitive differential), STI vs urinary pathogen distinction by age/risk factors, epididymal abscess (a complication of inadequately treated infection)

Natural history & complications

Torsion must be excluded before assuming epididymo-orchitis in any acute scrotal pain presentation - the two can mimic each other early on, and missing torsion while treating presumed infection risks losing the testis within hours

6 more sections, plus exam facts

Premium unlocks every note across every specialty, and the full exam fact library behind it.

Get premium access