Shingles, which is also known as herpes zoster, is a reactivation of the varicella, or chickenpox, virus. When a person is exposed to the varicella virus, either by vaccine or by the normal disease process, the virus does not leave the body completely but lies dormant for many years in certain cells in the nervous system. Later on, usually when the immune system has been weakened, the virus can be reactivated and travel down the nerves to the skin. Groups of blisters appear on the skin in very well defined areas. Where the rash appears is dependent on which nerve cells contain the virus. It can occur anywhere on the body but most commonly appears on the trunk.
In general, the rash itself is not significant, unless it occurs in a particularly sensitive area, such as around the eye. The blisters themselves only last a few weeks, and secondary bacterial skin infections are uncommon. However, the pain associated with the rash can last for weeks to months and, in some cases, years. The pain is often described as debilitating and can severely affect a person’s quality of life.