Hi lestypuss,
My DD Charlotte has a dry/eczma looking patch behind one of her knees too. She's had it for months and months- I can't remember when it appeared. It does flare up from time to time. Once when it flared up I found a sample pot of sudocream that I had laying around. Now, her dry patch has not been diagnosed as eczma or anything, but it looks like eczma to me. Sudo cream is supposed to help with eczma and nappy rash among other things. So I tried it on. It definately calms down the flare up- the dry patch never disappears completely. I often put it on nice and thick just before bed. You can buy sudocream from coles or woolies in the baby section.
I hope this helps!!!
Jess x o