"One of them recommends using soap only for "pits and bits" :) But as runners both, that's hard to do when covered in sweat and salt."
I switched to natural soap bars a while ago, as I like those anyways more than typical body washes one gets from e.g. cvs or walmart. For hair, shampoo every time is simply not necessary. I use that 1x a week, but some people don't use it at all- check out nopoo. I don't have issues with my scalp but my dermatologist did mention that Head and Shoulders can make eczema issues worse because it's abrasive.
I will check that book out.
"But its getting out of control. I was reading that itching from eczema drives people to suicide, just like dry eyes"
While I don't have those thoughts, I completely understand it. I'm not sure if people who've never had this kinda of eczema before can understand it. But the constant itching (which is both physical and mental) and the mess afterwards from scratching is brutal after a while. Scratching at 3am (after sitting in bed and trying to concentrate on anything other than the immense signal to scratch) brings a brief bout of euphoric relief, then regret and depending on the size of the scab, blood/sticky fluid. I basically had to wash my sheets and blanket daily because there would be residue all over.
For a while, the backs of my thumbs both kept on weeping. So imagine sticky fluid getting on your keyboard, guitar, etc and constantly having to wipe it. The same happened to the entire back of my right hand as it had gotten a bit infected, so I had to go to the ER and get a corticosteroid (dexamethasone) shot to calm the situation enough that it could get back to "normal"- scabs and immense itching urges.
"Which you may want to check out because of IgE. It goes into how typical antihistamines don't work because the itch signal is from a different pathway, etc."
This is something that I have been noticing too. I took benydryl occasionally and it seemed to have no real effect other than maybe placebo. Same with hydroxyzine- I've taken at max 100mg (4 25mg tablets) about 30 mins before bed, and the only thing it did was make me real sluggish the next morning / sleep through alarms.