Initial onset of symptoms which often include tingling and itching with normal appearing skin. THIS IS WHEN YOU SHOULD BEGIN PRESCRIPTION TREATMENT!
Around 24 hours after "the tingle", small blisters begin to form on lips. This is when they become painful
Withing several days of appearing, the blisters begin to pop, leaving red open sores
The cold sore blisters then begin the crusting stage, where they dry out and look brown or yellow
The crusted blisters begin flaking off, and the healing stage begins.