Weird skin rashes, and bumps the past month?

about july 21 my neck was a bit itchy and when i scratched it i got a rash the size of a peach on my neck which took about 3 days to go away, then my collar bone was itchy and it turned into a rash but only for a few hours. I was outside tanning and i got a rashe on my leg and stomach but that went away 20 min after i got out of the sun. Then about a few days after that i got a rashes where my skin would rub up agaisnt eachother. and then yesterday i got 3 bumps that turned red, and are somewhat itchy on my upper leg and today i got another one by my knee. does anyone no what the hell this is!? i didnt use any new products, im not sure about laundry detergent, i went to get a pedicure but nothing is by my feet and that was after my first few rashes. i dont think anything bit me. any ideas? suggestions?|||Heat rash?? I got this a couple times the past month. It gets itchy and when you scratch it stings, bumps develop as well.. If that's what you've got put a cool compress on it (I slept with an icepack in a towel) It takes about 3 days to go away.