Figure out what he's reacting to. Eczema is a fungus that lives n the colon and presents on the skin. To get rid of it you need to find the problem. The biggest culprit is dairy protein, which is found in cows milk.
Cut out dairy, start him on a good probiotic and a good fish oil supplement. Acidophilus probiotic will replace the bad bacteria with good and fight the fungus in his colon. The fish oils will help rebuild new healthy skin once the probiotic takes care of the fungus.
No cream will ever solve true eczema, no salve or steroid, no lotion or anythign will cure it. You have to cure it from the inside out.
My oldest son had such a bad case of eczema, he now has psoriasis too. His was from dairy protein, and his skin was literally falling off in chunks, oozing and bleeding, peeling off, boils, it was hideous and painful. We went through years of creams, steroids lotions and even oral medications before someone finally let us in on what really caused it, and after two months of taking acidophilus, fish oils and avoiding dairy his skin was starting to regrow. Now its been 3yrs and with this routine his skin has not boiled, fallen off, been bleeding or crusty.