What Is The Treatment For Itchy Rashes On The Legs?

first I got skin itching and rashes only on my leg. after it increases to the body. I took medicine under a skin doctors prescription. it goes when i am taking the medicines after that it comes again. Now what is the problem is i am getting throat or food pipe blockage, that time I cannot in take my food or water. My doctor said take decron and avil injection at that time. But I want to come out from this problem fully please help me sir