Epididymo-orchitis
From IDWiki
Background
- Inflammation of the epididymis with or without inflammation in the testes
- Historically thought to be caused mostly by STIs in patients under 35, and mostly by enteric pathogens in patients over 35, though this may be changing
Etiology
- Sexually-transmitted infection: Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and enteric bacteria (in patients who engage in insertive anal intercourse)
- Non-sexually-transmitted: enteric organisms (typically Enterobacteriaceae), often with history of recurrent urinary tract infection or recent urological procedures
- Rare causes:
- Mumps orchitis (without epididymitis)
- Tuberculosis
- Brucella
- Ureaplasma urealyticum
- Syphilis (case reports)
- Melioidosis
- Enterovirus, particularly in children and young men
- Candida
- Behçet disease
- Amiodarone toxicity
Clinical Manifestations
- Acute onset scrotal pain, typically unilateral, with or without swelling
- Tenderness to palpation
- May have urethral discharge or dysuria
- May have fevers
- May have hydrocele
Differential Diagnosis
- Testicular torsion, which is usually sudden onset and severe, and requires emergent surgery
Investigations
- Urinalysis and midstream urine culture
- Swab or urine for gonorrhea, chlamydia, Mycoplasma genitalium
- Ultrasound of the testicles
Diagnosis
- Clinical diagnosis
Management
- Suspected sexually-transmitted pathogen:
- Ceftriaxone 1 g IM once, plus doxycycline 100 mg p.o. twice daily for 14 days
- Either sexually-transmitted or enteric pathogen:
- Ceftriaxone 1 g IM once, plus levofloxacin 500 mg p.o. daily for 10 to 14 days
- Suspected enteric pathogen alone:
- Levofloxacin 500 mg p.o. once daily for 10 to 14 days
- Of note, levofloxacin preferred to ciprofloxacin due to better coverage for STIs
Further Reading
- The 2024 European guideline on the management of epididymo-orchitis. J Eur Acad Dermatol Venereol. 2026;40(2):166-173. doi: 10.1111/jdv.20865. Epub 2025 Jul 23. PMID: 40698982.
