I have both Addison's and Graves as well as lupus and other autoimmune problems. I have been on PTU for the Graves for close to 4 years now and every time I've tried to go off I've gone hyper very quickly. Just had my TSI levels tested again last month and they are still very high so I don't plan on going off the meds any time soon. When the thyroid is hyper it greatly speeds up the metabolism and I was burning through the steroids way too quickly and I ended up in adrenal crisis. Make sure your child is getting enough steroids. I felt awful. I currently take 15 mg of Pred a day which I realize is a high dose for Addison's, but with the lupus and stuff my body has become extremely touchy and I haven't been able to get the Addison's under control. I also have Graves Eye Disease, which if your daughter has, she needs to be monitored by an ophalmologist. If you have any questions, let me know. --Jenn G.