herpes simplex
"Works pretty darn good. You have to apply it diligently though- every 2 hours. Do not apply gobs of it but a thin layer with a Q-tip. Throw away the Q-tip so you don't cross contaminate!! Use Abreva right when you notice your lip tingle or itch. I also ice my lip for as long as I can stand to prevent the virus from replicating. It loves a warm environment. Ice kills it. I recommend icing, then applying a fresh layer of Abreva and taking Valtrex or acyclovir (1G). It should prevent your sore from growing and possibly eliminate it entirely if you catch it quickly enough."