Following a course of chicken pox, most of the varicella viral organisms are killed, however some survive and lay dormant within a person's nervous system for many years. With a decline in the strength of a person's immune system, the varicella viruses may reemerge and cause shingles. Shingles is an infection of the nerves which manifests itself on the skin corresponding to the affected nerves. It takes the form of a rash of small, crusting blisters, which within three days flatten and dry, and crust over. Within two weeks, the crusts drop off and may leave small scars.
Pain following an attack can be serious, and affects approximately one-third of shingles sufferers.
The pain is a result of damage to the nerves and causes strong nerve impulses to be produced and passed to the brain. This pain may last for months, and in some cases for years. Shingles affect approximately a few hundred people per 100,000 each year, with the greatest incidence in people over 50 years old. Treatment is usually in the form of analgesics to reduce pain, however antiviral drugs may be administered in the early stage of the outbreak to reduce the severity of the rash and to potentially reduce nerve damage.