Herpes zoster (HZ) is a nervous system infection caused by the varicella virus, the same virus responsible for chickenpox Figure 01. Herpes zoster (also called shingles) is an infection that primarily occurs in adults 50 years of age or older. Herpes zoster can occur at any time during a given year, and its key symptom is pain. Herpes zoster it is caused by the same virus responsible for chickenpox. Transmission of the virus to someone who has never had chicken pox and has not received the chicken pox vaccination is possible. Such transmission would result in a case of chicken pox, not in a case of herpes zoster illness, however. Shingles, which causes a lot of pain and discomfort, can now be mostly prevented by the recently-approved shingles vaccine.
Figure 01. Chickenpox
In HZ, the varicella virus travels from the spinal cord to the nerve endings in the skin, where it causes an infection Figure 02. After an initial chickenpox infection, the varicella virus travels from the skin into the nerve endings until it reaches the nerves that lie along the spinal column. There, the virus can remain dormant in the body for many years. Factors such as a weakened immune system and psychological stress help the virus to reactivate, spread, and multiply within the nerve cells. The virus then travels along the sensory nerve system until it reaches the nerve endings in the skin, where it produces an HZ rash.
Figure 02. Reactivation of dormant HZ infection
- Common Side Effects of AntidepressantsFind out about common and not-so-common side effects of antidepressants and how to manage them.
- How Drugs Can Lower CholesterolDiscover how cholesterol-lowering medications work in your body to bring your cholesterol numbers down to ideal levels.
- Do Over-the-Counter Proton-Pump Inhibitors Work?You might wonder why you need a prescription for GERD if many PPIs are available over the counter. Get the answers to this and other questions about OTC PPIs.