I Suffer From Constant Itching, It Is Not Localized, I

I suffer from constant itching, it is not localized, I have been tested for allergies, and I am allergit to grass and trees. I have been to the doctor and been given a sreroids shot it help but not for long. I have bee suffering from this problem for 15 years. The only thing I have found to work is Zantic D. but it contains pseduephedrene. I live in North Carollina and am limited to how much ephedrine I can by a month. I have been to numerous doctors, allergist, and to a doctor who specilized in skin. do you have any recommendations.