I noticed a blister like oval on my lower leg this morning. It looked like a burn injury, but clearly, I had not burned myself. This evening when I checked it after just putting Neosporin on it, there was a liquid in it, just a little, but when I pierced it, water-like liquid oozed out of it and now I have a burning pain but before had no pain at all. Could it be an insect bite or a cactus needle?