They look like hives to me. I have never seen a mosquito bite do that before. My daughter (when she was about 3) broke out with hives so bad that her feet swelled where she couldn't walk. I also would suggest benadryl for the itch. You really should see a doctor. I wouldn't fool around with stuff like that...what if your throat starts to swell...THAT would be a bad thing. Hope you find out what it is and your feeling better soon..
And WHAT THE HECK is a chigger??
That poor person in that photo!! I hope to GOD that was you (the poster)!