I have suddenly developed 3 blisters on my upper left arm. one is the size of a dime and filled with liquid to the popping point. The other 2 are about 2 inches away from the first, about a half inch apart from each other, and also have fluid. Thes two blisters are minute in size. These are not caused by burns. Strangely. the same thing happened about a month ago on the same arm, but only one large blister appeared then. I woke up with these blisters, which makes me think they may be bug bites, but I am not aware of any bugs that leave blisters. I am concerned because this seems so strange, and no one I know has seen nor heard of this before. Lastly, the first blister, which kept popping and refilling with liquid, left a dark scar about an inch long. Any ideas?