I have a sister who is prone to getting cold sores after dental work. The herpes simplex 1 virus never goes away. It's always hanging around, lurking, waiting for a weakness and that's when it hits. It's very common. Roughly 2/3 of people carry it.

She actually keeps Valtrex on hand so the minute she feels that little bit of a tingle she starts taking it. It helps quite a bit.

That's sort of the key. If you can take the Valtrex before it really breaks out, you can minimize it. Once it breaks out, it still helps, just not as much. Tough to put that cold sore genie back in the bottle.

It's going to be painful and unsightly but I don't believe it should have any real impact on her surgical recovery. Definitely get her medication though. Every little bit helps.