Could it be my water?? Or detergent?

Do you think the water I shower with can be causing my severe eczema? Or the detergent I use? I've been using Tide for many years. Can I all of a sudden be allergic to that? The bottle doesn't even list what's in it. Do you know if there is some kind of testing for these things that an allergist can do? My dermatologist is useless. Just tells me it's atopic dermatitis and no cure and take these steroid creams and prescriptions. Everything has alcohol in it and that makes my skin itch. Thanks so much for your help! I'm desperate!! Tweet