London - Being prone to recurring cold sores isn’t just the luck of the draw.
Scientists believe those plagued by the painful blisters don’t make enough of a protein that keeps the virus behind them under control.
By the time we reach adulthood, up to 90 percent of us have become infected with the cold sore-causing herpes simplex virus type 1 bug, but only 25 percent endure frequent outbreaks.
To find the reason for this disparity, Edinburgh University scientists looked at how cold sores occur.
The HSV-1 bug is usually caught through a kiss from a family member or friend with a cold sore. It travels up a nerve, where it lies inactive until a trigger such as stress, sunlight or illness awakens it.
By analysing thousands of genes, researchers discovered one that makes a protein, Interferon-lambda, that stops the virus from being reactivated.
They compared the DNA of frequent cold sore sufferers to those who had the virus but were rarely troubled by it.
In the former, the gene for Interferon-lambda was flawed. Around a quarter of Britons have the genetic defect, the journal PLoS Pathogens reports.
In rare cases, HSV-1 can have fatal side effects including brain-swelling, so Interferon-lambda could be used as a treatment.
But the risk of side effects mean it’s unlikely to be used for cold sores which clear up easily. - Daily Mail