New York, Jan 3 (IANS): Having shingles - painful, blistering skin rashes - may increase the risk of having a stroke years later.

"Anyone with shingles, and especially younger people, should be screened for stroke risk factors. Studies are needed to determine whether vaccination can also reduce the incidence of stroke and heart attack,” said study author Judith Breuer of University College London.

People aged 18 to 40 who had shingles were more likely to have a stroke, heart attack or transient ischemic attack (TIA) - warning for a stroke - years later than people who had not had shingles.

People over 40 who had shingles were more likely to have a heart attack or TIA, but not a stroke, than those who had not had shingles, said the research published in Neurology, the medical journal of the American Academy of Neurology.

The researchers involved 106,600 people who had shingles and 213,200 people of similar ages who did not have shingles. They reviewed the participants' records for an average of six years after the shingles diagnosis and for as long as 24 years for some participants.

“People under 40 years old were 74 percent more likely to have a stroke if they had had shingles, after adjusting for stroke risk factors such as obesity, smoking and high cholesterol,” said Breuer. The numbers were not as large in people over 40.

Shingles is caused by the same virus that causes chickenpox. After people recover from chickenpox, the virus stays dormant in the nerve roots. In some people, the virus reactivates years later as shingles.

“However, what is also clear is that factors that increase the risk of stroke also increase the risk of shingles, so we do not know if vaccinating people can reduce the risk of stroke. Current recommendations are that anyone 60 years and older should be vaccinated. The role for vaccination in younger individuals with vascular risk factors needs to be determined,” concluded the study.