My son has eczema and has pretty much since birth. He is one and a half now, and it is pretty well under control. He was formula fed, so I did not try any elimination diets. We do use only free and clear detergent, and Dr Bronners baby Castile soap for him. This was one of the only baby soaps I found that was unscented. The doctor also told us not to allow him to re-wear clothes, b.c the dried sweat could irritate it.
Try running his laundry through an extra rinse after washing it. And try cutting in half the amount of detergent you are using. That made a big difference for us. If you are using dryer sheets or anything, stop. We also got rid of all of his synthetic fiber clothing, b.c those outfits seemed to make it worse. Fleece was especially bad for it (he was a winter baby). I keep him in all cotton, and that helps a lot.
When it is dry out, I run the humidifier in his room at night. That helps a lot as well.
Another thing we did was to bathe [name]Levin[/name] only once a week for about the first year. Frequent bathing can make it worse, and a small baby just isn’t going to get dirty enough to need a daily bath.
We normally use Eucerin now that he is older and doesn’t want to sit still to get buttered up every few hours. When he was littler, we used mainly [name]Shea[/name] butter and coconut oil.
The downside w. [name]Shea[/name] butter and coconut oil is that you have to reapply a lot. Coconut oil is a little greasier than shea butter. They both work though, and allergies to either of those are pretty rare. Make sure you get a high quality [name]Shea[/name] butter if you do this, b.c the cheap ones often have bits of the nutshells in them. You can find it at natural foods stores, or online. You can get coconut oil in the regular grocery store w. the cooking oils b.c people like it for frying.
Be really careful w. sun exposure, b.c that makes it worse, too. And if you take him swimming, wash him off right away b.c chlorine and salt do not help.
If these measures don’t help though, I would use the prescribed cream. I understand about being uncomfortable about it, but it is better than it getting infected. I hope it gets better soon!