Hi Branca,
Welcome to the Moms Panel! Bless your little girl's heart. I truly hope her condition isn't painful.
They likely will not question you about it and if by chance they do, just explain that its not contagious. If you feel more comfortable taking a letter from her doctor just in case, then get one. My son was broken out from head to toe from allergies on one of our trips. At first I wanted to put a sign on him stating that he wasn't contagious but no one questioned us. After a bit I relaxed and didn't think twice about it.
I am sure that you know all of this but just be sure that you take all the precautious necessary to protect her from the sun. Depending on the time of year you visit, the sun can be very hot in Central Florida and then there is the humidity as well. My boys always wear swim shirts and if she's very venerable to the sun, I'd suggest a long sleeve swim shirt. A hat and sunglasses are good ways to protect her face. My boys often wear a hat with a flap that covers their necks and ears. Apply sunscreen often. Go early or after 3 p.m. to avoid the most intense rays. Be sure to keep sunscreen (approved for her condition) on and reapply often.
I'd plan to be at Typhoon Lagoon as soon as it opens to get a spot in the shade. If she needs a break from the heat and sun, you can take her to the
First Aid location in the park to cool her off a bit. We have found that rainy days (as long as its warm and not storming) are great days to head to the water parks. You're going to get wet anyway and the crowds are lower.
Please feel free to visit with any other questions. It is our pleasure to assist you!
Wishing you and your little princess minnie magical memories :-) Allison