Researchers in Taiwan found that people who had shingles had a higher risk of having a stroke than people who did not have it. They said more attention should be paid to shingles patients who have other risk factors for stroke, such as smoking, diabetes and high blood pressure.
The study was the work of lead author Dr Jiunn-Horng Kang, attending physician in the Department of Physical Medicine and Rehabilitation and chair of the Sleep Physiological Lab at Taipei Medical University Hospital, and colleagues, and was published online on 8 October in Stroke a Journal of the American Heart Association.
Kang told the press that:
“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.”
Shingles, or herpes zoster, is a painful skin rash caused by the varicella zoster virus (VZV), the same virus that causes chickenpox. It is not the same virus cause the sexually transmitted genital herpes disease.
It usually starts as a blistery rash on one side of the face or body accompanied by localized pain, itching or tingling. The blisters scab after three to five days and usually clear within two to four weeks.
VZV stays in the body after you recover from chickenpox, which often strikes in childhood. For most people the virus just stays dormant their whole lives, but for others, it can reappear many years later, causing shingles.
Kang and colleagues found that adults who had shingles had a 30 per cent higher risk of having a stroke within a year than adults who didn’t have it.
They also discovered that when the shingles infection was around and in the eye, the risk of stroke could be four times greater.
For the study, Kang and colleagues examined data on 7,760 patients 18 years and older who were treated for shingles between 1997 and 2001. They matched them with 23,280 controls: adults who weren’t treated for shingles. The average age of the participants was 47.
When they looked at the follow up data covering the 12 months after treatment, the researchers found that 133 of the shingles patients (1.7 per cent) and 306 of the controls (1.3 per cent) had strokes.
After adjusting for other factors normally linked to stroke risk the researchers found that:
- Patients treated for shingles were 31 per cent more likely to have a stroke, compared to those who did not have shingles.
- Patients with shingles that affected the eye itself and the skin around it (herpes zoster ophthalmicus) were 4.28 times more likely to have a stroke than patients who did not have shingles.
- Analysing the strokes by type showed that shingles patients were 31 percent more likely to develop an ischemic stroke during the 12 months of follow-up, and the risk of hemorrhagic (bleeding) stroke was 2.79 times higher for people with shingles than for people who did not have it.
According to the American Heart Association, every year about 780,000 Americans have a new or recurrent stroke, 87 per cent of which are ischemic, that is, caused by a blockage in an artery.
Kang said:
“Herpes zoster infection is very easy to diagnose, and antiviral medication can be used to treat the infection in the early stages.”
“While the mechanism by which shingles increases stroke risk remains unclear, the possibility of developing a stroke after a shingles attack should not be overlooked.”
The study did not look at how shingles might raise stroke risk, but other studies have found that as the virus spreads through and attacks the walls of blood vessels, it damages them and they become inflamed. This causes the blood vessel to close or get narrow, resulting in a blockage of blood flow to the brain, which causes stroke.
Shingles is also the only human virus known to invade arteries in the brain.
Kang said that shingles can be very painful and perhaps the stress of that chronic pain also raises the risk of cardiovascular disease.
He also warned that:
“Doctors and patients must pay extra attention to controlling other risk factors for stroke, such as high blood pressure, smoking and diabetes.”
“Increased Risk of Stroke After a Herpes Zoster Attack. A Population-Based Follow-Up Study.”
Jiunn-Horng Kang, Jau-Der Ho, Yi-Hua Chen, and Herng-Ching Lin.
DOI:10.1161/STROKEAHA.109.562017
Source: AHA.
Written by: Catharine Paddock, PhD