It could be a chemical sensitivity. My daughter's eczema was caused by chemical reactions. She's allergic to formaldehyde, chlorine, fluoride, preservative, and artificial colors.
What are you using for laundry? I had switched to free & clear detergents, tried elimination diets, blood allergy tests, etc.
What eliminated her eczema once and for all was getting all the chemicals out of our house, cleaning, diet, etc. We started shopping from Melaleuca (online) and within 3 weeks of converting our home (rewashing her clothes, sheets, towels, my clothes, etc.) her eczema was gone. That was 3.5 years ago and she's been eczema free ever since.
I was so impressed with the results I started telling friends about it and they started shopping from Melaleuca as well. I'm happy to help you with any questions you may have.
C.-WAHM of ~5 y/o virtual twins
Owner: http://www.BeHappierAtHome.com