What kind of bug bite is this on my toddler's leg?

my 2 1/2 year old had what started out like a mosquitoe bite i guess. couple nights ago she woke up middle of the night whinning about her "booboo". but she was scratching it so i figured it was just a mosquito bite because she was outside the night before and, it felt like one. so i just rubbed the bump a little she went back to sleep. later that morning she said it was still itching so i put some witch hazel on it. that was the first time i had ever used witch hazel on her. couple hours later when she was playing i notice that it had turned into a blister. she said it hurt when it touched it. and i was wondering if maybe it was some other bug that bit her and was not a mosquito bite or maybe it was the witch hazel i put on it. when i checked it out again later that day it had popped. so i applyed some antibiotic ointment and a bandaid. so i have some pictures of what it looked like before and after the bilster popped. i have picture with the flash on and off. and i didnt crop so i hope they're clear enough to see. has anyone seen anything like this before and know what it might be? here is the link to the album http://s746.photobucket.com/albums/xx104/NicoleKi78/Nivie%20blister%20bite%20on%20leg/