Epididymo-orchitis (testicular infection) is a bacterial or viral infection of the testicle and epididymis. The sperm produced in a testicle passes into a dense network of fine tubes that forms a lump on the back of the testicle called the epididymis. These join up to form the sperm tube (vas deferens) that takes the sperm to the penis. Epididymo-orchitis is an infection of both the epididymis and testicle. Orchitis is an infection of the testicle alone, but the infection is almost invariably present in both places.
Men with a bacterial epididymo-orchitis are acutely uncomfortable, have a painful swollen testicle, and a fever. Occasionally an abscess will form, which must be surgically drained. A painful testicle can also be caused by torsion of the testis, which is a surgical emergency requiring immediate treatment. Any boy or man, particularly in the teenage years or early twenties, who develops a painful testicle, must see a doctor immediately – day or night.
Blood tests may show the presence of infection in the body, and treatment involves appropriate antibiotics, aspirin or paracetamol for pain relief, ice may be applied to the scrotum, and a supportive bandage or jockstrap worn. If the infection is caused by a virus such as mumps, there is no effective treatment available. With the correct treatment, bacterial epididymo-orchitis resolves in a couple of days, and usually does not cause any problems with fertility or masculinity. In cases of viral infection there may be problems with fertility in later life.