From the Guidelines
Epididymitis is primarily caused by bacterial infections, with Chlamydia trachomatis and Neisseria gonorrhoeae being the most common causes in men under 35, and gram-negative enteric organisms such as E. coli being more common in men over 35. The causes of epididymitis can be broken down into two main categories: sexually transmitted infections (STIs) and non-sexually transmitted infections. In men under 35, STIs such as chlamydia and gonorrhea are the most common causes, as noted in the 2018 update by the Infectious Diseases Society of America and the American Society for Microbiology 1.
- Key points to consider:
- Sexually transmitted epididymitis is usually accompanied by urethritis, which is often asymptomatic 1.
- Non-sexually transmitted epididymitis is more common in men over 35 and is often associated with urinary tract infections, prostate infections, or urinary tract instrumentation 1.
- The diagnosis of epididymitis can be made using nucleic acid amplification tests (NAATs) for Chlamydia trachomatis and Neisseria gonorrhoeae, and culture for other bacterial pathogens 1.
- Treatment typically involves antibiotics, with doxycycline being recommended for suspected STI-related cases and fluoroquinolones for enteric bacteria 1.
- Non-infectious causes of epididymitis include trauma, autoimmune reactions, or chemical inflammation from urine backflow.
- Symptoms of epididymitis include scrotal pain, swelling, and sometimes fever, and prompt treatment is essential to prevent complications like abscess formation or reduced fertility.
From the Research
Causes of Epididymitis
The causes of epididymitis can be categorized based on the age of the patient and the likely causative organisms.
- In children younger than 14 years, the most common cause of epididymitis is considered to be reflux of urine into the ejaculatory ducts 2.
- In sexually active males between 14 and 35 years of age, the most common pathogens are Neisseria gonorrhoeae and Chlamydia trachomatis 2, 3.
- In men who practice insertive anal intercourse, an enteric organism is also likely to be the cause 2.
- In men older than 35 years, epididymitis is usually caused by enteric bacteria transported by reflux of urine into the ejaculatory ducts secondary to bladder outlet obstruction 2, 4.
Common Pathogens
The common pathogens responsible for epididymitis include:
- Chlamydia trachomatis 3, 5, 6
- Neisseria gonorrhoeae 2, 3, 5
- Enteric bacteria such as E. coli 4
- Coliform bacteria 3
Other Causes
Other causes of epididymitis include: