Apologies, I haven't read the full thread, just the OP - but it sounded so similar to my experience I thought I'd 'share'.
My DD (now 18mo) was similarly allergic to all the creams we tried - aveeno, doublebase, oilatum etc etc. Dermasalve was EXCELLENT but now they've gone into administration - however, I've found a new range called Allergenics (availble widely online, just google), and have been using the lotion, which is working a treat, and we now only have to use steroid cream every few days if that. (plus also finding out she was allergic to milk/eggs and cutting those out has helped)
I think my DD is allergic to the preservatives found in most conventional creams, and parabens (if they're not the same thing?!) - plus the usuals which exacerbate my own eczema, eg lanolin, fragrance (even 'natural' fragrance like lavender) etc. So the Allergenics range is def. worth a try.
Also, re the washing - we use Surcare (I've used it myself since I was a teenager with eczema); always make sure give the clothes an extra rinse cycle, and don't use conditioner. Also, try to use 100% cotton clothes, keep them as cool as possible, and whatever you do, don't put wool or fleeces directly next to the skin.
Sorry again if repeating other's posts, but thought the Allergenics range was so unusually good, worth mentioning.... Hope that helps....