S.G.
Have the doctors considered A-typical chicken pox? My daughter "mysteriously" broke out in hives after having cold-like symptoms. The dr tried telling me it wasn't hives and wasn't an allergic reaction. We had no fever and no itching. I had to insist the dr look closer and explained that lotions, warm "aveno" baths, etc. weren't helping. Also that more "spots" had cropped up since the previous night. After closer inspection she diagnosed my child with "A-typical chicken pox". She said this is the strain they get even when they've had the vaccination. Nothing to do but let it run it's course.
Good luck!