Good question, Louise!  I’m an adult with LOCAH on dex.  This fall I caught a nasty respiratory bug that triggered off my asthma pretty bad.  I was very short of breath and exhausted from the lack of oxygen.  My doctor (PCP) first had me increase my rescue inhaler to four puffs every hour, way above usual dose (usually 2 puffs no more than 4 times daily), but it did hardly anything to help me.   She then said she wanted me to start on prednisone (very common steroid to help in breathing problems, by the way), but admitted she was unsure how this would affect my system given the dex, and didn’t know exactly what to do.  SHE told me to call my endo and ask her, and gave me the prescription with the instructions not to fill it until my endo gave me the OK.  My PCP also said that the endo might tell me to stress dose, instead of adding prednisone or perhaps even in addition to the prednisone, since I was so sick.

My endo told me to take the prednisone in addition to the dex, and that I didn’t need to stress dose since I was adding another steroid anyway.  It was short term until my lungs cleared up a bit.

Of course, this was specific to my case, but still thought I’d share the experience since it was still pretty fresh.  Being on dex is still pretty new to me -- I never wanted to be on steroids and with LOCAH, it was kind of optional for me until last year, when my symptoms took a sudden and dramatic turn for the worse.  From what I’ve read on the board, the amount of dex I need to control my LOCAH is quite high compared to others -- thus the stress dosing questions and such. 

Good luck to your daughter!