Orchitis is an inflammation of one or both of the testicles, often caused by infection.

Orchitis may be caused by number of different types of bacteria and viruses. It is usually a result of epididymitis, inflammation of the tube that connects the vas deferens and the testicle.

The most common viral cause of orchitis is mumps. Approximately 30% of patients who have mumps will develop orchitis during the course of the illness. It is most common in boys past puberty, and rare before the age of 10. It usually develops 4 to 6 days after the mumps occur. In one-third of boys who get orchitis caused by mumps, testicular atrophy (shrinking of the testicles) will result.

Orchitis develops in 2 - 20% of men with the rare disease brucellosis.

Orchitis may also occur along with infections of the prostate or epididymis and may occur as a result of sexually-transmitted diseases (STD) such as gonorrhea or chlamydia. The rate of sexually-transmitted orchitis or epididymitis is higher in men 19 to 35 years old.

Risk factors for non-sexually-transmitted orchitis include:

• Inadequate immunization against mumps
• Being older than age 45
• Recurrent urinary tract infections
• Congenital problems of the urinary tract
• Genito-urinary surgery
• Long term use of a Foley catheter (tube inserted into the bladder to drain urine)

Risk factors for sexually-transmitted orchitis include:

• Multiple sexual partners
• Other high risk sexual behaviors.
• History of a sexual partner with a previously diagnosed STD
• Personal history of gonorrhea or other STD

• Scrotal swelling
• Tender, swollen, heavy feeling in the testicle
• Tender, swollen groin area on affected side
• Fever
• Discharge from penis
• Pain with urination (dysuria)
• Pain with intercourse or ejaculation
• Groin pain
• Testicle pain aggravated by bowel movement or straining
• Blood in the semen

A physical examination may reveal tender and enlarged lymph nodes in the groin (inguinal) area on the affected side. It may also show a tender and enlarged testicle on the affected side. A rectal examination may reveal an enlarged or tender prostate gland.

Testing may include:

• Urinalysis
• Urine culture (clean catch) -- may need several samples, including initial stream, mid-stream, and after prostate massage
• Tests to screen for chlamydia and gonorrhea (urethral smear)
• CBC
• Doppler ultrasound
• Testicular scan (nuclear medicine scan)

Antibiotics will be prescribed if the infection is caused by bacteria. In the case of gonorrhea or chlamydia, sexual partners must also be treated. Pain medications and anti-inflammatory medications are also commonly prescribed.

When orchitis is caused by a virus, only analgesics (pain relievers) are prescribed. Bed rest, with elevation of the scrotum and ice packs applied to the area, is recommended.

With appropriate diagnosis and adequate treatment of bacterially-caused orchitis, normal function of the testicle is usually preserved.

Mumps orchitis cannot be treated and the outcome is unpredictable. Sterility has followed mumps orchitis.

Orchitis may cause infertility and atrophy (diminished size) of one or both testicles.

Other potential complications include scrotal abscess, testicular infarction, cutaneous scrotal fistula and chronic epididymitis.

Acute pain in the scrotum or testicles is a surgical emergency. If you experience acute pain in the scrotum or testicles, seek immediate medical attention.

Call the local emergency number (such as 911) or go to the nearest emergency room if you experience an acute onset of testicular pain.

Immunization against mumps will prevent mumps-associated orchitis. Safer sex behaviors, such as monogamy and condom use, will decrease the chance of developing orchitis as a result of a sexually-transmitted disease.