What is it in the shortening that the kid is allergic to?
You can find (by shopping around a bit) shortenings that don't contain certain allergens (usually the biggest culprits of corn and soy and gluten).
Try stopping by the library or bookstore and picking up "Vegan Cupcakes take over the world"... there's some recipes for egg and dairy-less frostings and buttercreams in the back.
(sorry for the mispost... still figuring out the boards!)
He is allergic to soy... all the shortening I have found is make with soybean oil. Thanks for the heads up on the book though. I will definitely check it out. He can have corn syrup in moderation so that is why am going to use the MMF to on it. I was just hoping to find some sort of frosting/icing I could use to make a "Blue" on the MMF. I thought the royal would be good if I could get away without using the meringue in it.
I will see if that book has any options that I could use in it. Thanks again!!