What Is The Remedy For Itchy Rash?

Hi, I am getting red patches on my skin sometimes all of a sudden and i get rashes also. I am using omnacortil 15mg daily as per doctor's advice. But how long do I need to take that. I do not see any permanent solution to my problem. If I stop taking it, I get rashes and patches with irritation. Please suggest. Thanks for your help in advance..