Shingles is an infectious and painful skin rash caused by the same virus that causes chickenpox. This virus is called the Varicella zoster virus (VZV) and belongs to the herpes family of viruses.
Once a person has chickenpox, even after recovery the virus is never completely eliminated from your body but remains dormant in the nervous system.
lo immunity e.g. from HIV/AIDS or chemotherapy, canceror other debilitating diseases, the virus is reactivated and travels along the nerve endings to the sking surface to cause shingles.
Often the exact reason the virus gets reactivated is unknown. Everyone who has ever had chickenpox infection can potentially develop shingles in later life, however it is most commonly found in people over the age of sixty. It is believed that in the United States up to 1,000,000 cases of shingles occur yearly.