I cant give you any advice, but I can relate to your problems, first time I'v seen someone else with eczema, I got it around my navel, and on the back, 3 spots following my spine. My doctor has told me it looks like something related to some sort of inflammation in my intestines. Because it varies in, often come and goes with how I feel, if it's a bad period it will be much more active, and fade slowly away if everything is good, but never completely gone.
I'm to having several of your symptoms, constipation on and off, dizziness, tingling and cold hands.
I'm also currently experiencing breathing problems, chest tightness and coughing and a sore throat (like its a lump in the throat).
I'v also been trough the 24h Ph-test with similar results. I'm currently on no medication, I may have to go back on one, but I prefer not too, and have started the "Fast Tract Diet", but it's to early to give you any results.
Not much help in me, but I felt our symptoms was very much alike, best wishes to you.