I use to break out with rashes like this all the time when younger. For me the only things that helped reduce pain, swelling & hive like clusters was cold cold showers. I keep reading about people take hot showers. Wow that seems painful. It's basically a huge open sore... I could not image hot water on it. My thinking was the cold water closed the pores. About 4 cold showers a day help tremendously! Also Benadryl seemed to help. I keep reading that people say it doesn't spread. Anyone that has experianced this type of reaction tends to disbelieve this.