Can a outbreak be just ONE blister?

Yes it is possible to only have one blister. I've had it for about 10 years now. For about 5 years I only got one blister and always in the same spot. I also only got them once or twice a year. Then one day it changed and now I usually get one or two and they are in one of three different spots. But occasionally when I get really stressed or anxious I end up getting it in new spots. The last few years I have been battling with anxiety and I get it almost monthly now. Last month I was so overwhelmed and close to a couple of panic attacks. I also was eating a lot of pasta and had a lot of caffeine. I ended up getting the worst outbreak I've ever had. It was in a new spot and consisted of about 5 blisters clustered together. I also have friends in the same situation.