Shingles (herpes zoster) is a painful, blistering skin rash due to the varicella-zoster virus, the virus that causes chickenpox.
Causes, incidence, and risk factors
After you get chickenpox, the virus remains inactive (becomes dormant) in certain nerves in the body. Shingles occurs after the virus becomes active again in these nerves years later.
The reason the virus suddenly become active again is not clear. Often only one attack occurs.
Shingles may develop in any age group, but you are more likely to develop the condition if:
- You are older than 60
- You had chickenpox before age 1
- Your immune system is weakened by medications or disease
If an adult or child has direct contact with the shingles rash on someone and has not had chickenpox as a child or a chickenpox vaccine, they can develop chickenpox, rather than shingles.
Review Date: 05/25/2010
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.