Shingles Raises Stroke Risk: Study
THURSDAY, Oct. 8 -- Adults with the skin disease shingles appear to be at raised risk for stroke, especially when it affects the area around the eyes, researchers report.
Previous reports have linked shingles with stroke risk, but "the exact frequency and risk for these phenomena are still unknown," said study lead author Dr. Jiunn-Horng Kang, a principal investigator in the Neuroscience Research Center of Taipei Medical University Hospital, Taiwan. His team published their findings in the November issue of Stroke.
"Our study is the first to explore these issues with a nationwide population-based data," Kang said.
Shingles is a painful skin rash resulting from infection by the varicella zoster virus, which causes chickenpox. The virus remains in the body after recovery from chickenpox and can erupt again to cause shingles.
Kang and his colleagues studied data on 7,760 adult Taiwanese who were treated for shingles between 1997 and 2001. In the year after treatment, 133 of them, or1.7 percent, had strokes. The incidence in a control group of 23,280 adults who were not treated for shingles was 1.3 percent (306 people).
Analysis of the data found that the risk of stroke in that one-year period was 31 percent higher in the shingles group. The incidence was dramatically higher for those with a shingles infection in or around the eye -- nearly 4.3 times higher than in the control group.
Strokes can be ischemic, caused by a blood clot blocking a brain artery, or hemorrhagic, due to rupture of a blood vessel. The study found a 31 percent higher incidence of ischemic strokes, the most common kind, and a 2.79-times higher incidence of hemorrhagic stroke in the shingles group.
"The major mechanism of our findings is that stroke results from herpes zoster virus-induced vasculopathy [blood vessel damage]," Kang said. "The vessel to the brain damaged by the virus could be occluded [blocked] or ruptured."
"However, several other factors could also be involved," he added.
No known treatment exists to reduce the apparent risk of stroke that results from shingles infection, Kang said. "Our interest and ongoing research are focused on whether early anti-viral treatment for herpes zoster can reduce the risk of stroke," he said. "Also, from the clinical view, patients who have a shingles attack should be aware of the risk of stroke, and intensive monitoring and management of pre-existing risk factors for stroke, such as hypertension, hyperlipidemia [raised lipid levels] and diabetes, should be emphasized."
Shingles usually starts as a rash on one side of the face or body, which often causes pain, itching and tingling. Attacks can last for two to four weeks. The incidence of shingles increases with age, and the U.S. Centers for Disease Control and Prevention recommends most people over 60 be vaccinated against the virus, with the major exception being those with weakened immune systems.
While there have been scattered reports about a possible association of shingles with stroke, "to my knowledge this is the first study to link shingles very specifically with stroke," said Dr. Daniel Lackland, professor of epidemiology and medicine at the Medical University of South Carolina, and a spokesman for the American Stroke Association.
"It might be a little too early for a lot of clinical implications here," Lackland said. "But a physician who is treating someone with shingles should emphasize the importance of traditional risk factors for stroke, and let the patient know that your risk might be a little bit increased and you should pay more attention to high blood pressure, cholesterol and the like."
Learn the basics about shingles from the U.S. National Library of Medicine.
Posted: October 2009