Suggest Treatment For Skin Rashes With Pus Filled Pimples

I get terrible skin rashes, it looks like small white pus filled pimples all over my face...I am not sure what causes it, but I used to get it regularly now not so much. but when I do it itches. The itching is how i know I am getting the rash, then small non pus pimples will appear after that they fill with pus and takes weeks to dry up. I normally use soda power to dry it up and some rubbing alchol to cure it. Can u please tell me whats the cause and how to solve it....thanks