What Are Cold Sores?
Cold sores are highly contagious, painful blisters that appear on the mouth. They can appear alone or in clusters and usually clear up on their own after 2-4 weeks. Cold sores are estimated to affect between 50-90% of the adult US population.
What Causes Cold Sores?
Cold sores are caused by the herpes simplex virus, and most commonly by a specific strain known as HSV-1. The other strain (HSV-2) is the one that usually causes genital herpes, although this is not true in every case.
Cold sores are not exclusively an STI and can be caught from any type of skin-to-skin contact. Kissing and oral sex can spread the herpes simplex virus but so can sharing items like lipstick and food.
It is estimated that at least 50% of American adults have the cold sore virus in their bodies, but only a portion of them ever show symptoms.
Whether the carrier shows symptoms or not, the virus can be passed on to the people they come into close contact with. While anyone can catch it, children under 3 years old are most susceptible to infection.