herpes simplex
"Abreva was a god-send. I  to apply at the first tingle and cold sore would not even develop . 
 Fast forward a couple of years , (about 1-2 sores tried to come out per year but I was successful in full stop) Abreva no longer works. 
It even appears to spread the blisters? I no longer feel the numbing sensation that I used to from the abreva cream. 
I'm so disappointed ! I feel like I may have become immune to the cream or else the formula has changed."