Shingles. Artwork of varicella-zoster virus particles (virions, blue) during shingles. Each viron comprises an icosahedral (20-sided) capsid containing viral DNA, surrounded by surface protein spikes. When this virus is reactivated from an earlier chicken pox infection, it causes shingles or herpes zoster. The virus travels along sensory nerves to the skin where it causes small blisters (red), usually on the trunk or face. The blisters last around two weeks and, if untreated, nerve damage causes severe pain in the affected area. Reactivation may be associated with stress or reduced immune function. Antiviral drugs, like acyclovir, can help if taken early on.