What is the cycle of a coldsore?

Herpes simplex : Cold sores are caused by the hsv1 virus. Initially, the cold sore appears as a cluster or single vesicle or blister on a red base. Over a few days, the blister opens and becomes crusted and then heals over the course of 1-2 weeks. The severity and length of the outbreak can be reduced using creams such as abreva or oral prescription anti-viral medications such as valtrex (valacyclovir).