Are there certain creams that prevent an outbreak of herpes?

Pills do, not creams: Cold sores are caused by herpes viruses which reside inside your body/nerve. The currently available creams/topicals can only treat, not preventing it. There are few pills you can take to suppress the frequency/severity of these outbreaks. Unfortunately, there is no cure yet. If you have frequent recurrences, consult doc for eval and treatment. Good luck.