Why do cold sores most commonly appear specifically on lips and not other parts of one’s face?

Question

Cold sores aka HSV-1

In: 62

Answer 1

More broadly, many viruses target mucous membranes. Your lips, parts of your genitals, your eyes are all mucous membranes.

HSV-1 is unusual because it only flares up at the original site of infection and even if you are re-infected with the virus, the original site is usually what flares up.

Thus lips and less commonly, genitals, are where the initial site of infection is because of human behavior: kissing, oral sex, genital to genital sex. It would be interesting to know if HSV-1 can infect the eyes or, say, mucous membranes of the respiratory system, but human behavior rarely has lips touching those things.

(If you are having a HSV-1 flare up, still avoid contact if possible. While the original infection site usually flares up, there’s some slight risk of complications with re-infection.)