I think that you are on the right track. I was a heavy drinker for many years and it took a toll on my immune system and ate away a the lining in my stomach. I believe this is where my patm began. I also believe that it's ammonia that coming through the pours of our skin. Our bodies aren't filtering it out like it suppose to. If you Google about this you'll see that this can cause itching and irritation. Also fatigue and some memory loss or not so clear thinking is common. I think that you are on the right track, and I agree with you 100% when you say that it's not all in our heads.