Last reviewed: 24 May 2025
Last updated: 14 May 2025
Summary
Acute epididymitis is inflammation of the epididymis causing pain and swelling that develops over the course of a few days and lasts <6 weeks. It is usually unilateral.
In sexually active men, epididymitis is most commonly caused by sexually transmitted organisms including Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium.
In older men, the causative organisms are often enteric pathogens, and epididymitis may be associated with bladder outlet obstruction, recent instrumentation of the urinary tract, or systemic illness.
Diagnostic tests include a Gram stain of urethral secretions, and urine specimens for nucleic acid amplification tests for C trachomatis, N gonorrhoeae, and M genitalium (where available). Urine microscopy and culture is also indicated if urinary pathogens are suspected.
Treatment relies on supportive measures, including bed rest, scrotal elevation, and analgesics, in conjunction with empiric antibiotic therapy based on the patient's age, and clinical and sexual history. Once diagnostic test results are available, antibiotics can be adjusted to target the causative organism(s).
If C trachomatis, N gonorrhoeae, or M genitalium are the confirmed or suspected pathogens, evaluation and treatment of the patients’ sexual partner(s) is essential to prevent reinfection and ongoing transmission.
Definition
Acute epididymitis is inflammation of the epididymis characterized by scrotal pain and swelling of less than 6 weeks' duration.[1]Taylor SN. Epididymitis. Clin Infect Dis. 2015 Dec 15;61 Suppl 8:S770-3.https://www.doi.org/10.1093/cid/civ812http://www.ncbi.nlm.nih.gov/pubmed/26602616?tool=bestpractice.com It may be associated with irritative lower urinary tract symptoms, urethral discharge, and fever. It is usually unilateral. The condition is referred to as acute epididymo-orchitis if concurrent inflammation of the testis is present. The acute presentation of epididymitis will be covered.
History and exam
Key diagnostic factors
- age >19 years
- unilateral scrotal pain and swelling of gradual onset
- symptoms <6 weeks' duration
- tenderness
- hot, erythematous, swollen hemiscrotum
- frequent and painful micturition
- purulent urethral discharge
Full details
Other diagnostic factors
- pyrexia
- fluctuant swelling or induration of scrotal tissue
- enlarged or tender prostate
Full details
Risk factors
- unprotected sexual intercourse
- bladder outflow obstruction
- instrumentation of urinary tract
- immunosuppression
- vasculitis
- amiodarone
- mumps
- exposure to tuberculosis (TB)
Full details
Log in or subscribe to access all of BMJ Best Practice
Diagnostic tests
1st tests to order
- Gram stain of urethral secretions
- urine dipstick test
- urine microscopy
- urine culture
- nucleic acid amplification test (NAAT) of urethral secretions or first-void urine for Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium
- culture of urethral secretions
Full details
Tests to consider
- scrotal color duplex ultrasonography
- surgical exploration
- 3 early morning urine samples for acid-fast bacilli staining, culture, and NAAT for Mycobacterium tuberculosis
- HIV test
- syphilis test
Full details
Log in or subscribe to access all of BMJ Best Practice
Treatment algorithm
ACUTE
bacterial infection
amiodarone-induced
underlying vasculitis
idiopathic or viral
tuberculous
Log in or subscribe to access all of BMJ Best Practice
Contributors
Authors
Ameeta E. Singh, BMBS(UK), MSc, FRCPC, FIDSA
Clinical Professor
Division of Infectious Diseases
University of Alberta
Edmonton
Canada
Disclosures
AES declares that she has no competing interests.
Acknowledgements
Dr Ameeta E. Singh would like to gratefully acknowledge Dr Hossein Sadeghi-Nejad, Dr Lorenzo DiGiorgio, Dr Mary Garthwaite, and Dr Ian Eardley, previous contributors to this topic.
Disclosures
HSN, LDG, and MG declare that they have no competing interests. IE is a consultant to Pfizer, Lilly, and Sanofi. He is a speaker for Lilly.
Peer reviewers
Sheldon Morris, MD, MPH
Assistant Professor
Division of Infectious Diseases
Department of Medicine
UCSD Antiviral Research Center
Division of Family Medicine
Department of Family and Preventive Medicine
UCSD La Jolla Family and Sports Medicine
San Diego
CA
Disclosures
SM has received research funding support from NIH CHRP, CIRM, and Gilead Sciences. He has financial interests in Impact Biomedicines (now Celgene) and Forty Seven Inc. There is no conflict between these financial interests and any content in this topic.
Altaf Mangera, MBChB (Hons), MD, FRCS (Urol), FEBU
Consultant Urologist
Department of Urology
Royal Hallamshire Hospital
Sheffield
UK
Disclosures
AM declares that he has no competing interests.
References
Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.
Key articles
Chirwa M, Davies O, Castelino S, et al. United Kingdom British association for sexual health and HIV national guideline for the management of epididymo-orchitis, 2020. Int J STD AIDS. 2021 Sep;32(10):884-95.Full textAbstract
American College of Radiology. ACR appropriateness criteria: acute onset of scrotal pain - without trauma, without antecedent mass. 2024 [internet publication].Full text
Workowski KA, Bachmann LH, Chan PA, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep. 2021 Jul 23;70(4):1-187.Full textAbstract
Street EJ, Justice ED, Kopa Z, et al. The 2016 European guideline on the management of epididymo-orchitis. Int J STD AIDS. 2017 Jul;28(8):744-9.Abstract
European Association of Urology. Guidelines on urological infections. Mar 2022 [internet publication].Full text
