Shingles is a disease that is caused by the same microorganism that causes chickenpox in children. Shingles usually occurs in adults who have had chickenpox in their past and is characterized by a skin rash with blisters. Shingles is technically called herpes zoster and it is caused by the varicella zoster virus (VZV). After becoming infected with VZV as a child, the virus can become latent and reside in specific nerve cells for many years with no sign of illness. In some cases, the virus can become re-activated and travel down the nerve cells to infect the skin in the region with a rash. That is why shingles tends to be localized to a particular part of the body. The exact reason for the latent virus becoming reactivated years later is not understood.