Eczema is a curious beastie. Some types are exacerbated by stress. Was it the vacation or the salt water pool, or something else? In your husband's case it worked...this time.
What does the dermatologist say? That's your best bet for a cure.
But if you want a fun treatment go to Window Rock, Arizona and see if you can get one of the Navajo singers to put on a "sing" for you. An "enemy way" or "blessing way" sing lasts several days and nights..sweat baths, sand painting, chants..by Godfrey, when it's over you'll know you got treated for something.