She should ask how much Prednisone and how long as it has side effects and long term effects, I am trying to research it online as I have chronic Urticaria since May, (Hives) it may not have been the spider bite caused it she could be allergic to something, there is a very long and interestin thread on the Allergy site tell your friend to go there ,it gives severall ideas,what to do what to take, quite honestly I believe it will run its course and I will just have to put up with it,