herpes simplex
"Starting getting cold sores a few years ago and Abreva used to work but now I have used it last time and this time and not only does not work but appears to make it worse.  I usually only have one small one the whole time and it is gone in a few days. Now, both times I have used it, the one cold sore tripled and it bigger than ever.  Will not waste my money on this product anymore. They have definitely changed something and not for the better."