Joshua,
I don't have any known allergies, but when I was a young teen I experienced a horrendous case of hives, like Ole mentioned above. The doctor couldn't figure out what caused it, but he took photographs for a journal article and reference! I tell you this so you have a 'positive' in here with the other stories, your daughter may have had a reaction to the oak, but it could well be a one-off. I suffered no ill effects from the reaction (other than the itching at the time) and haven't had another case since. I hope your daughter gets well soon (mine is 21mo!), I'll be keeping you guys in my thoughts and hoping for a quick and easy resolution.
daniel
Not all chemicals are bad. Without hydrogen or oxygen, for example, there would be no way to make water, a vital ingredient in beer.