According to the Mayo Clinic, cold sores are closely related to genital herpes and can be spread through kissing and oral sex. Antiviral medications can help heal a cold sore, a process that takes up to two weeks.
Cold sores are typically dormant, and it’s believed that stress, chocolate, the menstrual cycle, caffeine and a weakened immune system are all culprits that can lead to an outbreak.
Cold sores can happen to anybody, says the Mayo Clinic, “about 90 percent of adults worldwide — even those who’ve never had symptoms of an infection — test positive for evidence of the virus that causes cold sores.”
Here are a few celebrities who were snapped out and about with an imperfect pout.