I have a friend whose son has not been diagnosed but shows many signs of Aspergers or sensory integration problems.  At any rate,  she has found that dramatically changing his diet has worked wonders.  With this thought in mind, it might not be the cortisone but the binding agent that is giving him fits.  By removing wheats and other grains (except rice I believe) , as one of many of the limitations, they are having success but they have to be very careful of presciptions because of what is being used to bind it.  Wheats are often used.  Or if you are having the cortef compounded into a liquid, it could be the artificial dye or flavor.

Anyway, that is just a thought.  Her son has had some backslides over time as they discover where some of these things are hidden.  it is frustrating, but the improvements have made it worth the effort.

good luck!