Cold sores suck! I never had one until I met my darling hubby. I don't *think* I've had one since dieting. I think that's because I eat less chocolate, an extremely rare bite actually, peanuts and caffeine. I read those might contribute to cold sores. I've also upped my salmon intake which contains lysine or something- read that lowers risk. I think (not sure) lysine is a good supplement if you get them regularly.
My dermatologist prescribed Valtrex for me to take if I feel one coming on.
I probably got them 3 or 4 times a year. None, knock on wood this year since eating better. There might be something behind the chocolate/cold sores because I really ate alot alot alot before changing my habits on January 1st.
Just found a link with some of the food culprits, it's listed under 'causes'...
http://www.health911.com/remedies/rem_coldso.htm
I'm a freak about my skin and panic like a diva drama queen if I think I'm getting one. I've found that applying ice to them before they erupt helps alot.