Updated: Jan 26, 2023
  • Author: Nataisia Terry, MD; Chief Editor: Erik D Schraga, MD  more...
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Practice Essentials

Orchitis is an acute inflammatory reaction of the testis secondary to infection. Most cases are associated with a viral mumps infection; however, other viruses and bacteria can cause orchitis. Testicular examination reveals the following: testicular enlargement, induration of the testis, tenderness, erythematous scrotal skin, edematous scrotal skin, and enlarged epididymis associated with epididymo-orchitis. On rectal examination, there is a soft boggy prostate (prostatitis). often associated with epididymo-orchitis. [1, 2, 3, 4, 5, 6, 7]

Up to 60% of affected testes demonstrate some degree of testicular atrophy. Impaired fertility is reported at a rate of 7-13%. Sterility is rare in cases of unilateral orchitis. An associated hydrocele or pyocele may require surgical drainage to relieve pressure from the tunica. In one study of 7 patients who were followed after mumps orchitis (4 unilateral, 3 bilateral), in the unilateral orchitis group, 1 patient had an atrophic testis, 3 had severe oligozoospermia, and 1 had mild oligozoospermia. In the bilateral orchitis group, none had atrophic testes, and findings of semen analysis revealed azoospermia in 1 and severe oligozoospermia in 2 patients. Findings of semen analysis in most patients improved gradually. [8]

Pubertal and postpubertal males who have not received mumps vaccination are more susceptible to the virus and have a high risk of mumps orchitis. [7]


Orchitis most commonly occurs with epididymitis. Epididymitis is usually bacterial in origin; the most common pathogen is Neisseria gonorrhoeae in men aged 14-35 years, and Escherichia coli is the most common cause in boys younger than 14 years and in men older than 35 years. Viral orchitis is most often caused by mumps infection but can also be caused by a nonspecific inflammatory process in the testes. [3, 9, 10, 11]

Approximately 20% of prepubertal patients (younger than 10 years) with mumps develop orchitis. Unilateral testicular atrophy occurs in 60% of patients with orchitis. [12]  Sterility is rarely a consequence of unilateral orchitis. Despite some anecdotal reports, little evidence supports an increased likelihood of developing a testicular tumor after an episode of orchitis.

Mumps outbreaks have resulted in substantial increases in cases of orchitis. The mumps outbreak in England in 2004-2005 resulted in an increase in orchitis cases of up to 2 to 2.5 times in some populations (those born in the 1970s and 1980s). In comparison, during the years of low mumps incidence following introduction of the MMR vaccine, mumps-related orchitis was significantly reduced in those who did come down with the disease. [13, 14]

In the Czech Republic, 2-dose vaccinations against mumps showed a significant preventive effect agains the mumps complications of orchitis, meningitis, and encephalitis. However, complications increased with the time interval after vaccination. [15]


The symptoms of orchitis usually present several days after parotitis. Isolated bacterial orchitis is even more rare and is usually associated with a concurrent epididymitis; it occurs in sexually active males older than 15 years or in men older than 50 years with benign prostatic hypertrophy (BPH). Symptoms of isolated orchitis usually resolve spontaneously in approximately 3-10 days, whereas epididymitis will usually resolve in a similar time frame after initiation of antibiotic treatment.


In sexually active males, urethral cultures and gram stain should be obtained for Chlamydia trachomatis and Neisseria gonorrhoeae. Urinalysis and urine culture should also be obtained.

Color Doppler ultrasonography is the imaging test of choice for acute testicular pain. [2, 16, 17]


Supportive treatment includes bed rest, hot or cold packs for analgesia, and scrotal elevation. With appropriate antibiotic coverage, most cases of bacterial orchitis resolve without complication.

If torsion is likely, urologic consultation is necessary for surgical exploration. In cases of significant hydrocele, urologic consultation is necessary.

If  enteric bacteria is suspected, fluoroquinolones (ciprofloxacin, ofloxacin, levofloxacin) are preferred; trimethoprim-sulfamethoxazole is an option. If a sexually transmitted pathogen is suspected,  treatment consists of ceftriaxone (250 mg IM) and doxycycline (100 mg twice daily for 10-14 days); azithromycin is  an alternative for doxycycline. [1]





Most commonly, mumps causes isolated orchitis. The onset of scrotal pain and edema is acute. Because mumps orchitis is responsible for most cases of isolated orchitis, diagnosis in the ED usually is based on a reported history of a recent mumps infection or parotitis with a presentation of testicular edema.

Other rare viral etiologies include coxsackievirusinfectious mononucleosisvaricella, and echovirus. Some case reports have described mumps orchitis following immunization with the mumps, measles, and rubella (MMR) vaccine.

Bacterial causes usually spread from an associated epididymitis in sexually active men or men with BPH; bacteria include Neisseria gonorrhoeaeChlamydia trachomatisEscherichia coliKlebsiella pneumoniaePseudomonas aeruginosa, and Staphylococcus and Streptococcus species. Salmonella is a rare cause of epididymo-orchitis that disproportionately affects neonates. [18] Bacterial orchitis rarely occurs without an associated epididymitis.

Immunocompromised patients have been reported to have orchitis with the following etiologic agents: Mycobacterium avium complex, Cryptococcus neoformansToxoplasma gondiiHaemophilus parainfluenzae, and Candida albicans.

Orchitis may have a noninfectious etiology. It occurs in 12-19% of men with Behcet disease, usually with more severe disease. Amiodarone-induced epididymo-orchitis has also been reported. [19]