I had that same thing happen. I had some left over prednisone. I treated just as you would a flare of asthma. They usually give the prednisone in a 5 or 7 day pack. I went 20mg the first two days, then 10mg for 2 days then 5mg and then 2mg. Then stopped. Pain was gone and did not return. Everything I have read your body stops producing cortisol at about 2 weeks. Inside that period of time you can make changes to your dosage. I had made a Dr. appointment but it was long gone by time I saw the Dr. I have had two of those episodes an treated both the same way. I had PMR 4 years ago and both these episodes were in the first year of being off.