Get some stuff called Zanfel. It's high, about $35 for a tube but it does work and it's worth it! It's a wash/soap stuff. If you see it coming on or know you had contact but no symptoms yet, wash with it.
It stops the stuff dead in it's tracks if it's showing up and keeps it from ever showing up if you wash after contact but before symptoms show.
Heard about it on Paul Harvey and tried it. I'm a believer after a year of using it.