Hi I Am Trying To Find Out What Could Be

hi i am trying to find out what could be causing issues with my 8yr old daughter. she has red bumps they kinda look like bites. they itch and she has them scratched opened. they r on her arms legs and one on her face. tonight after dinner she has got a rash on her chest and a little swelling and her belly is bloated as well a little. my own doctor cant even tell me what is causes all of this. it has happened to her 2 times before this one. what do i do and were do i turn. is it from something she ate???