Dr. Oanh Lauring, a dermatologist at Mercy Medical Center says, "Some people can just go out and have sun exposure and that's going to be enough to reactivate (cold sores). The more kind of extreme sun exposure, up to sunburns, you tend to have a higher probability of giving you recurrences."
Experts advice those exposed to the sun to use lip balm with sunscreen protection and use cold sore cream treatments as soon as a blister forms.
