I thought people might be interested in this article from a reliable source.
Something I forgot to mention at the time was that often people on pred find that as they reduce their dose they discover they are having allery-type reactions, mostly skin-related. This can be very common with certain types of hair dyes and you should ALWAYS do a patch test before using a dye - even if it is one you have used before. Allergies don't appear the first time you use a product - it can be the second or the thousand and second. Prevention is better than cure!