I am a 29-year old female, recently diagnosed with AS (ankylosing spondylitis). I also had spine surgery in July, for 2 thoracic discs that were herniated. I just started Humira last Thursday and weaned off of Prednisone that day as well. In the meantime, over the past 2-3 weeks, I have had a lot of pain in the area where I had my surgery. I am now on a 5-day steroid burst of Prednisone. I took the first dose of 25 mg today, and within a couple of hours, I began feeling like I had the flu...my entire body aches from head to toe. I have had this happen with a Medrol Dose Pack in the past, as well as after receiving an epidural steroid injection. Is this a common reaction from higher doses of Prednisone? It usually only lasts about a day or so, and then I wake up feeling better the next day.