Having shingles raises the risk of suffering a stroke by almost a third, according to a new study.
In a study reported in Stroke: Journal of the American Heart Association, adults with shingles were about 30 percent more likely to have a stroke during a one-year follow-up than adults without shingles.
The risk was even greater when the infection involved the eyes.
Shingles, also called herpes zoster, is a painful skin rash caused by the varicella zoster virus (VZV). VZV is the same virus that causes chickenpox.
After a person recovers from chickenpox, the virus stays in the body. Usually the virus doesn't cause problems, but it can reappear years later, causing shingles.
Shingles is not caused by the same virus that causes genital herpes, a sexually transmitted disease.
"Many studies have shown that people with herpes zoster infection are more likely to develop stroke. But ours is the first to demonstrate the actual risk of stroke following herpes zoster infection," said Jiunn-Horng Kang, M.D., M.Sc., lead author of the study and attending physician in the Department of Physical Medicine and Rehabilitation and chair of the Sleep Physiological Lab at Taipei Medical University Hospital.
Kang and his associates studied 7,760 patients 18 years and older who received shingles treatment between 1997 and 2001. These people were matched by age and gender with 23,280 adults who weren't treated for shingles (controls). Their average age was 47.
During the one-year follow-up, 133 shingles patients (about 1.7 percent) and 306 of the controls (about 1.3 percent) had strokes.
After adjusting for general factors for stroke risk, the researchers found people treated for a shingles infection were 31 percent more likely to have a stroke, compared with patients without a shingles infection.