OH MY GOSH I HAVE EGE...
anyway..
I react to pollen in the air; It causes hives and tummy pain in me. Have you recently changed your deoderant/soap/laundry detergent? That can have allergens in it, too, that cause hives and such. It could also be atypical keratosis pilaris; I have that as well. Try some OTC steroid creams you can buy at Wal-Greens or CVS. I know that a lot of people with EGIDs tend to have eczema, too.
When was your last allergy test? You may have developed a slight Ige reaction to something, as hives are an Ige reaction.
Hope I helped :)
--Fellow EGID-er