I have had these strange hive that can just appear like blisters on my arm or legs or head even oon my uppper eys lids. Even on my private area. I found as long as you don't itch them they go away within minutes. I have tried going off different foods. It is possible it has to due with red dye 40 or yellow dyes that are in gatorade or other energy drinks. It has seem to have gone away sense I stopped drinking them. So,when I buy drinks I make sure they have no dyse in them. Something sle I think it relates to is emotions. When my hives come out I either have to lay down or relaxe. The first time it happen I had this big sore on my buttocks. It was about 6 inches long and was blistery and full of fluid i thought it was a spider bite, so I popped it and put salt water on it. I beat the crap out of it. I finally went to the docter and he siad it look like shingles. This is what you get when you are over 50 and it comes from the chicken pox virus. I just don't think that is what it was. I do promise, I will figure this whole thing out i always do.