Jennifer - you should definitely see an allergist and have some tests done.  My son (who we just found out at age 6 is NCAH) had a rash all over as an infant and at 2 months we found out he was allergic to egg whites.  That lasted (had to test annually) until he was about 4.  However, he is my super sensitive skin kid and has always gotten hives or rashes at any new exposure - including different water when we travel to other places!  We know this because as an infant we would try to avoid the rash when we traveled to any relatives and would bring EVERYTHING including our own towels and washclothes.  He would still get the full body rash and the ONLY non-controllable thing was WATER!!!!

Anyway, he was prescribed by his allergist as a baby a cream that is a mixture of Acid Mantle Cream and 1% hyrdocortisone.  It has to be mixed at a pharmacy that does compounds which can be hard to find, but it is a GOD send!  We use it on him everytime out of the bath and can tell when we start to get lazy on that. 

Hives/rashes are a form of eczema which is an allergic reaction to something.  So, if you cannot figure it out and with your husband’s history, I think you would feel a lot better having an allergist try to get you some answers.  I have severe allergies and know what a relief getting on a program can be.  Hope this helps.