herpes simplex
"If you use Abreva at the onset of itching where the cold sore (herpes simplex) begins, apply it immediately at the dosage on the bottle (as with any prescription) - the cold sore does NOT crust over, this medication actually starts the healing process within by absorption. I'm just getting over one, and it was gone in 3 days without the crusty look, or scab formation that is the most embarrassing part of a cold sore and with Abreva; this does not happen. I highly recommend it, also, talk to your Dr. about Zovirax (Acyclovir). Using it in conjunction with the Abreva, works wonders!"