2 year old stress?!?!

This might seem very self explanitory but I thought I would see what suggestions were out there. My 2 year old step son developed hives on Sunday morning, out of the blue in a matter of minutes and for the last 3 days the causes have been explored and still we are in the dark. We were told this morning that he is 'stressed' and that is a possible and the most likely cause of it. Can he really be stressed to the point of hives? He is a very happy, energetic little guy who talks and is very nromal for 2. The catch is lately he has been upset about going to daycare, someplace that used to be one of his favorite places to be. Is it time to make yet another change in his life or do we just stay put and handle one issue at a time.

Thanks

[LRM1021]

1. Hives can be caused by stress. Pepcid, the stomach acid treatment, is actually a histamine blocker. Histamine is increased by stress (thus - stress can cause upset stomachs!)Histamine  also causes hives. When people have severe histamine-based allergic reactions, Pepcid is one of the treatments they give.
2. My son had something just like this when he was about 3. It was caused by a virus. He just had some hive periods that went on and off for about two weeks. They finally stopped when we gave him a full dose of Benadryl -- they went away for good. I'm not sure if the virus just left him or not.
3. Hives are also related to allergies. Has your son eaten anything different and/or been exposed to anything different and/or been adequately tested for allergies?