Ya know.. I didn't connect this, but I had eczema as a child too. It's gone away almost entirely now. I think ditching sugar and grains may indeed have something to do with that. My own bout with anorexia never seemed to affect it, though. Even moving from a dry desert climate to a wet coastal one didn't really improve it.
I think the soap advice is legit. It really dries the hell out of anyone's skin, and eczema makes skin prone to dryness and irritation anyway.
You may have subclinical food allergies, or just mild food intolerances. You'd have to do trial and error with that, though. I also routinely eat things I test as very allergic to- eggs, nightshades- and it's never affected my eczema one way or another.
Given that winter is bad in particular... maybe it's the climate? Dry climates get drier in winter, and the temperature change is very hard on your skin. Could be stress too. But the fact that it flares so faithfully with the grains is a big clue.
If it flares and refuses to budge... do you use a topical corticosteroid cream? When eczema gets all flared-up and inflamed, it usually can't resolve on it's own. The inflammation just feeds on itself, and most people basically have to scratch, it's almost impossible to completely avoid it. Some people can get it to heal up with OTC hydrocortisone, but I sure needed more firepower than that.
First Nations people here used glacial mud to treat eczema. And in my experience, it really helps a LOT. Sometimes I use a bit of my seaweed mud facial masks on any mild flares I get- now very rarely. But the whole glacial mud thing has gotten really trendy, and cosmetics manufacturers are even more prone to super-jack up the price as soon as they've got a real buzz-ingredient. Even more so than the Whole Foods crowd and their ultra-overpriced acai and goji berries, their $40 'designer lifestyle' matcha tea, their $50/bottle magic-omega 3 olive oil. So it may be better to just go for the prescription. Save your money.
And moisturize! But I think most women have been well-versed in the need to moisturize.
I'd say that if you don't see immediate dramatic triggering with the sweet potatoes or rice- both of which are gluten-free- they likely aren't involved. But you could do the full-primal thing anyway. Just to see what happens.
Getting my Grok on in the Pacific Northwest.
"C is for cookie, that's good enough for me."
"Cookie is a sometimes food."
"Sometimes cookie monster eat APPLE instead of COOKIE. Sometimes eat CARROT."
-Cookie Monster, partially reformed sugarholic