What's the difference between chicken pox and shingles? Is shingles contagious? Can it be treated or prevented?

The virus that causes chicken pox is also responsible for causing shingles. Shingles sometimes develops after a case of chicken pox when the virus, which hides in the nerves, becomes active again and migrates out to the skin.

Unlike chicken pox, which can be transmitted by a sneeze or cough, shingles is spread through skin contact. If someone who hasn't had chicken pox becomes infected, they can develop chicken pox, but not shingles.

Typically lasting about 30 days, shingles usually occurs only once during a lifetime, although people with depressed immune systems may get repeated attacks.

Shingles initially manifests as an itching or burning sensation in one area of the skin, which eventually becomes red and develops blisters. The condition is often quite painful, since it irritates sensory nerves. If shingles occurs on the upper face, it may involve the eyes.

In some cases, the area of the rash can hurt for a long time -- sometimes permanently -- after the infection has died down. Called "post-herpetic neuralgia," this long-term pain usually occurs in older patients.

Medications that interfere with the virus's growth may help decrease the chance of developing post-herpetic neuralgia, as well as reduce the severity and duration of the infection. Medications such as steroids, antidepressants or anticonvulsants may also help.

Your doctor can advise you of the best ways to treat and prevent shingles.