Bite Size Blister On Leg Large Itchy Blister On Leg.?

Large itchy blister on leg.? - bite size blister on leg

Two days ago, my 7-year-old daughter was playing outside and said he felt like was stung by an insect. He saw a small white label and noticed that he an insect bite. At night, the white label to a bubble was very hard, small, light, itchy legs. The next morning, the bubble had been a little larger than a coin. I took her to the doctor and had no idea. He said he thought it might bollous impetigo and prescribed an antibiotic. Online Photo bollous impetigo resemble anything you have. She took the antibiotic once so far. The bubble is now very large (the size of a silver dollar). The bladder was not clear last night, but now it is gray and white and harder than before. (It feels like a rock). It is unpleasant for themHiking and itching. I know that while only one in ten doses of antibiotics so far and maybe we should wait, but I am concerned. Has anyone an idea what might that be?