Q&A: virus-caused hives

Amy writes:

"My 23 month old son has been battling hives for the last 2.5 weeks.  Ata bad day, he'll have hives starting from his scalp all the way to the bottom of his feet and everywhere in between.  On a good day, he will have 3-4 patches on his stomach and groin area.  The doctor thinks this is due to a viral infection and put him on oral steroids and Benadryl - the steroids worked for a few days, but now the hives are back full force.  Because it's viral, there's not much we can do except just wait it out.  The doctor says it may take up to 6 weeks for it to completely subside!  (If it doesn't subside at that point, they'll start running some tests.)  Needless to say, the poor little guy is miserable and itchy and clingy, and I feel terrible about giving him Benadryl over and over again. 

Have you or any of your readers dealt with this?  Any home remedies to relieve the itching?"

I've got exactly nothing, except oatmeal baths. I might also try some kind of elimination diet to make it easier for his system to cycle through the virus and hives. (I'd cut wheat, and maybe dairy.) Readers?