Spud that's a good sign if it's not painful,herpes(shingles)can be very painful,usually before and during that blister stage,the chicken pox is a virus of the same nature and I understand our bodies can store it.I had a weird blister on my hand some years back on that is what it was,it came and went for awhile and it has not reoccured for a few years now,but it was painful,so I hope it's alright.Sumi