Shingles, also known as herpes zoster, are small, painful skin lesions caused by the same virus that causes chicken pox, the varicella zoster virus (VZV). Shingles usually occur in older individuals and in people who have weakened immune systems, such as organ transplant patients taking drugs to suppress their immune systems or people with acquired immune deficiency syndrome (AIDS). Shingles occur when the varicella zoster virus migrates along the sensory nerves to the skin surface. Along the way, the virus causes inflammation of these sensory nerves, causing severe pain. Shingles may persist for one to three weeks, and in some cases, may leave scars after they heal. Shingles usually heal without treatment, but pain medication is helpful. In some people, particularly older individuals, the pain may persist for months and even years after the shingles themselves have disappeared. This lingering pain probably stems from nerve damage.
The most common sites for shingles to erupt are the face and back; shingles are rarely found on the arms and legs. The eyes are sometimes affected by shingles. In some cases of shingles, the virus affects nerves in the face, a condition called Ramsey-Hunt syndrome. This syndrome is characterized by facial paralysis (Bell's palsy) and deafness, and may sometimes lead to encephalities, an infection of the brain. Other complications of shingles include bladder and bowel disturbances if the shingles affect the nerves that control these areas, and serious eye complications if the shingles affect the nerves that lead to the eyes.
Although the connection still is not clear, scientists theorize that some people who have been infected with varicella zoster virus continue to harbor the virus in their nervous systems. During times of stress or when the immune system is weakened, the latent virus reactivates, and then migrates down the sensory nerves to cause shingles lesions on the skin. This tenuous connection between chicken pox and shingles has raised concerns about the experimental chicken pox vaccine that is currently undergoing safety tests, since the varicella zoster virus used in the vaccine could theoretically lead to shingles later in life. However, no data is available that links an increased risk of shingles and the chicken pox vaccine.
Shingles are not life-threatening, but the severe pain associated with the lesions and their tendency to recur make shingles a serious health concern. No preventative measures can be taken. Antiviral drugs, such as acyclovir, may lessen the duration of the lesions. Steroids may also be helpful against pain that persists after the lesions heal.