In most cases a person's first indication that a cold sore is developing is that they notice a sense of Tingling or soreness, tautness, or swelling in the location where their cold sore will form. For the most part, this area looks normal, but can become slightly reddened compared to the surrounding tissue.
Blisters
STAGE 2: The "Blister Stage" (DAY 2-3)
This stage of the disease can be seen as blisters that are filled with a clear serous fluid resembling serum which is watery in nature. These blisters start out small and are usually clustered together or can form a larger blister.
Stage 3 The Ulcer Stage
STAGE 3: The "Ulcer Stage" (DAY 4-5)
This stage of the disease the fever blisters usually start to burst open. The tissue becomes a reddish ulcer with a surface that starts to turn grayish. Stage 3 is the most contagious time of the infection. The fluid from this wound contains the highest concentration of the "free" viral particles and anyone that comes in contact with the fluid could very well get infected. The common exchange of body fluids comes from kissing any moist tissue (lips, nasal tissue, eye lid, vaginal etc.). This is why this disease is commonly called "Kissing Disease". Grandma, that is infected passing the virus to a grand son or daughter. Once infected by this latent virus, one would carry the virus for life.
Stage 4 Scabbing stage
STAGE 4: The "Scabbing Stage" (DAY 5-9)
This is the time whereby the ulcers start to turn brownish and scab over. This is the most painful stage of the disease. More often the neurons or sensory receptors (nerves) are now infected which causes the pain. If the scabs are not kept moist, they can often will crack and can cause bleeding.
Stage 5 Healing
STAGE 5: The "Healing Stage" (DAY 10-14)
The last stage of the disease is the healing stage. Generally, there are a series of scabs that will form and then drop off as the wound gets smaller and smaller. In most cases, the fever blister resolves itself without scarring.