EpididymitisSwollen, sore and infected

Definitions

• Epididymitis – inflammation of the epididymis usually as a result of bacterial or viral infection, rarely as a result of trauma or urinary reflux from the urethra[1]

• Epididymo-orchitis – inflammation of both the testis and epididymis[1]

• Orchitis – inflammation of testis due to trauma, ischaemia, metastasis, mumps or infection elsewhere in the body[1]

Anatomy Review

Epididymitis

• Acute – pain and swelling < 6 weeks• Subacute – pain and swelling 6 weeks – 3 months• Chronic – pain > 3 months can be subdivided – inflammatory,

obstructive and epididmyalgia[2]

Incidence

• 13 cases per 10,000 Australian male patient encounters at the GP[3]

• 31 per 10,000 in age cohort 25 – 29 years[3]

• Similar in the UK[4] • 24 per 10,000 for all ages • 27 per 10,000 for the 25 – 34 year old cohort

Aetiology

• No exact causes identified• Urinary reflux (congenital, mechanical)• Presence of infectious agent• STI vs Urologic Pathogen[5]

Bugs Bugs Bugs

• Bacteria[5]

• Enteric bacteria (Pseudomonas and E Coli)• Tuberculosis• Syphilis• Gonorrhoea• Chlamydia

• Viruses• Coxsackie A6 virus (hand, foot and mouth disease)[6]

• Enterovirus and adenovirus [5]

• Hepatitis B [7]

• Mumps [8]

Other Aetiologies

• Trauma• Obstruction secondary to vasectomy• Fungal infections such as candida and histoplasmosis• Rheumatic conditions• Parasitic infection such as trichomoniasis and schistosomiasis [5]• Can be amiodarone induced [9]• Posterior urethral valves in children [10]• Xanthogranulomatous inflammation [11, 12]

Pathophysiology

• Infection limited by segmental nature of epididymis[13]

• Unilateral in acute setting with bilateral impact on spermatogenesis[14]

• Bilateral in chronic setting• Abscess• Segmental infarction[15]

• Fertility impact• 6 – 7% azoospermia, 22 – 37% oligospermia[14]

Diagnostic Criteria – Physical Signs[5]

• Pain – location of pain• Swelling – induration of scrotal sac• Surgical history• Sexual history

Diagnostic Criteria – Biochemical

• Urinalysis• Urine culture / gram staining of urethral discharge• Haematology – WCC and CRP• No specific serum inflammatory marker has yet been discovered for

epididymitis though work continues[16]

• Semen culture no longer necessary

Ultrasound of Epididymitis - Acute

• Increased PSV of testicular artery on affected side versus normal side[17]

• Epididymis / testis is thickened / enlarged• Echotexture may be heterogeneous and hypoechoic • Increased vascularity compared to surroundings under Doppler

interrogation• Reactive hydrocele[17]

Acute Features

Reactive Hydrocoele

Heterogeneous Echotexture

Increased Vascularity

Ultrasound of Epididymitis – Chronic

• Thickened epididymis / testis / tunica vaginalis• Induration of scrotal wall• Heterogeneous echotexture• Coarse calcifications• Testicular infarct – wedge shaped hypoechoic area [15]

Utility of Ultrasound

• Exclusion of testicular torsion / mass• Visualise extent of disease progress – abscess formation / secondary

infarction• Follow up of epididymitis – success of treatment

References 1. Taber's Cyclopedic Medical Dictionary. 22nd ed. Cyclopedic Medical Dictionary, ed. D. Venes. 2013, Philadelphia: F.A. Davis Co.

2. Shoskes, D.A., Urological Men’s Health : A Guide for Urologists and Primary Care Physicians. Current Clinical Urology, ed. E.A. Klein. 2012, Totowa, NJ: Springer: Humana Press.

3. Chen, M.Y., et al., Trends in clinical encounters for pelvic inflammatory disease and epididymitis in a national sample of Australian general practices. International Journal of STD & AIDS, 2006. 17(6): p. 384-386.

4. Nicholson, A., et al., Management of epididymo-orchitis in primary care: results from a large UK primary care database. The British Journal of General Practice, 2010. 60(579): p. e407-e422.

5. Michel, V., et al., Epididymitis: revelations at the convergence of clinical and basic sciences. Asian Journal of Andrology, 2015. 17(5): p. 756 - 763.

6. Vuorinen, T., et al., Epididymitis Caused by Coxsackievirus A6 in Association with Hand, Foot, and Mouth Disease. Journal of Clinical Microbiology, 2014. 52(12): p. 4412-4413.

7. Aydin, Ö.A., et al., An Unusual Extrahepatic Manifestation of Acute Hepatitis B Infection: Epididymitis. Viral Hepatit Dergisis, 2014. 20(2).

8. Doyle, J.S., E.K. Paige, and D.W. Spelman, Mumps presenting as epididymo-orchitis among young travellers: under-recognition, missed diagnoses and transmission risks. The Medical journal of Australia, 2011. 194(6): p. 317.

9. Nikolaou, M., et al., Amiodarone-induced epididymitis: A case report and review of the literature. International Journal of Cardiology, 2007. 121(1): p. e15-e16.

10. Kwong, J., et al., Bilateral Epididymitis in a Child With Undiagnosed Posterior Urethral Valves. Urology, 2013. 82(1): p. 225-227.

11. Ezer, S.S., et al., Xanthogranulomatous Orchiepididymitis: A Very Uncommon Cause of Scrotal Mass in Childhood. Urology, 2013. 82(1): p. 228-230.

12. Repetto, P., et al., Bilateral xanthogranulomatous funiculitis and orchiepididymitis in a 13-year-old adolescent boy. Journal of Pediatric Surgery, 2012. 47(10): p. e33-e35.

13. Stammler, A., et al., Epididymitis: ascending infection restricted by segmental boundaries. Human Reproduction, 2015. 30(7): p. 1557-1565.

14. Rusz, A., et al., Influence of urogenital infections and inflammation on semen quality and male fertility. World Journal of Urology, 2012. 30(1): p. 23-30.

15. Pearl, M.S. and M.C. Hill, Ultrasound of the Scrotum. Seminars in Ultrasound, CT and MRI, 2007. 28(4): p. 225-248.

16. Pilatz, A., et al., Clinical evaluation of human epididymis protein 4 as a biomarker for epididymitis. Biomarkers in Medicine, 2012. 6(3): p. 311-7.

17. Pilatz, A., et al., Acute epididymitis in ultrasound: Results of a prospective study with baseline and follow-up investigations in 134 patients. European Journal of Radiology, 2013. 82(12): p. e762-e768.

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