HERPES ZOSTER

Herpes Zoster

Herpes Zoster

Definition, Etiology, and Risk Factors

Herpes zoster, also called zoster or shingles, is a painful skin rash caused by the varicella zoster virus (VZV), the same virus that causes varicella or chickenpox.

After a person recovers from chickenpox, the virus remains dormant in nerve tissue. However, the virus can become active again years later and cause shingles. Any person who has had chickenpox is at risk for shingles, though shingles most commonly occurs in persons older than 50 years. Shingles is also more common in persons with weakened immune systems resulting from human immunodeficiency virus infection, chemotherapy treatment, radiation treatment, transplantation surgery, and stress. In the United States, an estimated 1 million cases of shingles occur each year.

Most commonly, a person has only 1 episode of shingles in his or her lifetime. Although rare, a second or even third case of shingles can occur in some persons.

Very rarely, shingles can lead to pneumonia, hearing problems, blindness, encephalitis, or death. About 1 in 5 persons also has PHN, a condition characterized by pain that persists after the rash has resolved. Older persons are more likely than younger persons to have PHN.

Diagnosis of Herpes Zoster

To diagnose herpes zoster, a dermatologist looks at the appearance of the skin and asks if the patient has experienced pain before the rash developed. To confirm the diagnosis, a dermatologist may scrape skin cells from a blister onto a glass slide for examination under a microscope. Also, the blister fluid containing the virus can be sent to a laboratory for special testing.

Causes of Herpes Zoster

It is not clear what reactivates or "awakens" the virus. A temporary weakness in immunity (the body's ability to fight infection) may cause the virus to multiply and move along nerve fibers toward the skin. Although children can get zoster, it is more common in people over the age of 50. Illness, trauma, and stress also may trigger zoster.

We do know that people with a weakened immunity are prone to developing zoster. A variety of illnesses and medical treatments can weaken a person's immunity. These include cancers, AIDS, treatment for cancer such as chemotherapy or radiation, drugs taken to prevent rejection of a transplanted organ, and cortisone when taken for a long time. All can make someone susceptible.

While much less contagious than chicken pox, a person with zoster can transmit the virus by means of direct skin contact if blisters break. Newborns and those with decreased immunity are at the highest risk. If someone contracts the virus, the person develops chicken pox — not zoster. Shingles only occurs after a person develops chicken pox and the virus re-emerges in certain nerve cells.

Signs and Symptoms of Herpes Zoster

Zoster typically causes more pain and less itching than chicken pox. A person may feel burning, itching, tingling, or extreme sensitivity on the skin (usually limited to an area on one side of the body). These symptoms are typically present for one to three days, sometimes more, before a red rash appears in the same ...