My sis and I are both sufferers from bites and they blow up just like you said, and have tried everything. The only thing I find is to try and avoid getting bitten in the first place, so I tend to make sure I try and keep covered up whenever the little bs are about. They always seem to ignore the chemicals. There are some anti itching creams and sprays which often work, but don't do what my wife did to her brother recently. He complained about a bite on his forehead and asked if we had anything to prevent itching, so she gave him some Anusol, which he happily rubbed on, without realising what it was. Now I'm under pain of death not to tell him! Jokes about bites on the butt or about having piles of them are also off-limits!