The latent herpes-a virus is often triggered by trauma to the mouth area.
Don’t let your lips (mucous membranes) get severely dry, use a lip balm.
Excessive UV exposure (sunlight/sunburn) also triggers the virus, use a lip balm with an SPF of 15.
Medicated lip balms containing menthol help in the healing process, also.
I get them after a visit to the dentist but sometimes mine are caused by stomach upset/reflux. If that’s the case, I drink buttermilk.
That reminds me that I need to drink some buttermilk. I have lost two pounds in seven days since the husband thing. LOL I might as well get ahead of the sores.
Do try not to use poison sun screen especially around your mouth. Bees wax will do just fine.