Out of nowhere I suddenly developed 4 rashes on my upper thigh on one side of my body. They almost look like cat scratches and wrap around the front of my thigh to the back. A few hours after they first appeared blisters began forming in the lines. These blisters are smooth and clear-filled (Not scaly). I also have one random blister on the opposite side of my body on one of my knuckles. These rashes hurt when touched but do not itch. What could this be?