Fever Blisters/Cold & Cankers Sores > Cold Sores > Canker Sores

Type 1
Herpes simplex virus type 1 ("HSV1") generally only infects those body tissues which lie "above the waistline" and it is HSV1 which causes cold sores in the majority of cases.

Type 2
Herpes simplex virus type 2 ("HSV2") typically only infects those body tissues which lie "below the waistline" and it is this virus which is also known as "genital herpes". Herpes simplex virus type 2 is not usually the virus which causes cold sores, although it can.

How do people get exposed to the herpes simplex virus which causes their cold sores?
When you think of having an infection you usually assume that you were recently exposed to the germ which has caused your problem. With cold sores this is not the case. Cold sores are not a sign of a recently acquired herpes simplex infection but instead a reactivation of virus particles already living in your body. Cold sores occur when latent herpes simplex virus, which has been lying dormant ("asleep"), becomes reactivated.

Where does this dormant herpes simplex virus come from?
The dormant herpes virus particles come from a previous infection. A person's initial herpes simplex virus infection, termed "primary herpetic stomatitis", does not usually take the form of a cold sore, and thus you may not relate your initial exposure to the herpes virus to the recurrent cold sores you get. What are the signs and symptoms of a person's initial herpes (HSV1) infection?

The classic "full blown" symptoms of a person's initial infection of the herpes simplex virus (termed "primary herpetic stomatitis") takes the following form:

• The first signs of the infection are characterized by nonspecific constitutional symptoms such as: fever, irritability, headache, and possibly pain upon swallowing.
• A day or so after the infection's initial signs have appeared the person's mouth becomes painful and their gums become intensely inflamed.
• Usually by day three of the infection a number of tiny blisters have formed throughout the person's mouth.
• These blisters soon rupture resulting in grey colored ulcers.
• These ulcers can be very painful and commonly interfere with a person's ability to eat.
• The ulcers will eventually heal. Usually the entire infection has run its course within 10 to 14 days.

Why don't the symptoms of primary herpetic stomatitis seem familiar to you?
If you don't remember having had the classic signs and symptoms of primary herpetic stomatitis it might be because you experienced them as a small child. Most cases occur before the age of 7.

Additionally, if you don't remember having all the classic signs and symptoms, it's probably because your case was subclinical. This is by far the most common occurrence. It has been estimated that 99% of all cases of primary herpetic stomatitis are subclinical, meaning that the course the infection ran was so slight that its symptoms were not apparent. It is quite possible that when you had the infection that, at most, you only experienced one or two mild mouth sores.