Fever Blister / Cold Sore question?

Hi I am 27 years old and I have never had a fever blister or a cold sore on my lips before. I do however get canker sores alot in my mouth and have since I was about 11 years old. I talked to a friends wife (she is a LPN) and she asked me if I had been really stressed out at all the last couple days and 4 days ago my son had a asthma attack and it freaked me out. Hes ok and all but at the time it was a scary thing to witness. She told me stress was one of the most common causes of fever blisters. I told her that this was the first one I had ever gotten and she then asked me if I have ever had chicken pox and I have not once but twice. She said anyone that has had chicken pox can get a cold sore/fever blister. Is all this true? I mean I know shes a nurse and all but I find it odd that just out of no where for the first time in my life I get one of these on my lower lip. Any help would be great :) Thanks

It sounds like a herpes lesion, probably caused by herpes simplex virus 1 (HSV1) also known as human herpes virus 1 (HHV1) although it also may be caused by herpes simplex virus 2 (HSV2) or human herpes virus 2 (HHV2.) These viruses are notorious for causing cold sores, particularly on the lips. Reactivation of the virus from nerve ganglia leads to outbreaks. These outbreaks can be triggered by a number of things including stress.

If the outbreak becomes particularly bothersome, you may see a physician about treating it with antiviral drugs such as acyclovir or valcyclovir (valtrex.)

Chicken pox is caused by varicella zoster virus (VZV) or human herpes virus 3 (HHV3.) Although it has many similarities to HSV1 and HSV2, it doesn't usually cause sores in the mouth or lips. It's reactivation can cause shingles, but would probably not be the cause of your sores.