Health Topics A-Z

What Is Shingles?

Shingles is a reactivation of the herpes zoster virus, the virus which causes chickenpox. With shingles, the first thing you may notice is a tingling sensation or pain on one side of your body or face. Painful skin blisters then erupt on only one side of your face or body along the distribution of nerves on the skin. Typically, this occurs along your chest, abdomen, back or face, but it may also affect your neck, limbs or lower back. The area can be excruciatingly painful, itchy and tender. After one to two weeks the blisters heal and form scabs, although the pain often continues.

The deep pain that follows after the infection has run its course is known as postherpetic neuralgia. It can continue for months or even years, especially in older people. The incidence of shingles and of resulting PHN rises with increasing age. More than 50 percent of cases occur in people over 60. Shingles usually occurs only once, although it has been known to recur in some people.

What Causes It?

Shingles arises from the same virus, herpes zoster, that causes chickenpox. Following a bout of chickenpox, the virus becomes dormant in the spinal nerve cells, but it can be reactivated years later at a time when the immune system is suppressed — by physical or emotional trauma or a serious illness, or by medications which suppress the immune system. Medical science doesn't understand why the virus becomes reactivated in some people and not in others.