A case of shingles may increase the risk of your having a heart attack or stroke, at least in the short term, researchers say.
Following an initial diagnosis of shingles, also known as herpes zoster, a transient increased risk can arise in the months immediately following, a study from the London School of Hygiene and Tropical Medicine found.
Shingles, more common in older adults and people with compromised immune systems, is caused by the reactivation of the chicken pox virus.
Anyone who has ever had chicken pox is susceptible to some level of risk of subsequently getting shingles, which affects around a million Americans every year.
The study findings suggest the risk of stroke doubles in the first week following a diagnosis of shingles, the researchers say, and the risk of heart attack also increases, although not as much.
The risk of either appears to return to normal levels within six months, they report in their study appearing in the journal PLOS Medicine.
"The study highlights when patients with shingles may be most vulnerable," suggests study author Caroline Minassian, a researcher in epidemiology and population health at the London school.
For the study, the researchers analyzed data on nearly 43,000 U.S. Medicare recipients diagnosed with both shingles and stroke from 2006 to 2011.
They also looked at 24,000 shingles patients who suffered a heart attack during the same period.
The average age of the patients involved was 80; around two-thirds were women and about 90 percent where white.
The finding only suggests a link between shingles and stroke or heart attack, not a proven cause-and -effect, the researchers emphasize.
The study "did not look at the mechanisms involved in the associations," Minassian says.
"However, possible reasons might include the overall higher level of inflammation in the body associated with a viral infection, or [virus-induced] blood vessel damage," she suggests. "Acute increases in blood pressure relating to shingles-associated pain or stress may also play a role."
In 2006, a vaccine became available that succeeded in cutting the risk of shingles by 50 percent, while reducing the severity of symptoms in those stricken with the condition.
Shingles is not the only condition that can impact cardiovascular health, experts point out; influenza, pneumonia and urinary tract infections have been linked to similar increases in the risk for heart complications.
A similar study linking shingles with heart attack and stroke, conducted by U.S. researchers, has been published in the Mayo Clinic Proceedings.