I have a friend whos little boy was allergic to chocolate. She took him to the doctor and she asked him about the white chocolate also. He said it just depends on the person, some are allergic to both and some are allergic to just one and not the other.
I hope this helps you.
It probably depends which ingredient in chocolate the person is allergic too. White chocolate isn't chocolate as such because it doesn't contain any cocoa so if it is this that the person is allergic to I see no reason why they would be allergic to white chocolate.
Ah ok, maybe it's not chocolate because it doesn't contain the cocoa bean? What is it that gives chocolate the brown colour then? Well whatever that is, white chocolate doesn't have it. If someone is allergic to that then they should be ok with white chocolate. Point made?
I think white chocolate has cocoa butter but not cocoa solids.
Cocoa powder is just the solids, while good milk or plain chocolate has both. Cheap chocolate replaces much of the cocoa butter with other vegetable fat.
It's the solids which give it the oomph -- the more the better for us chocoholics (though the 98% stuff is a bit of a challenge) -- can't see the point of white chocolate.