Oh, you are probably going to hate my answer - it depends. The answer with steroids is to use the lowest dose, for the shortest time, that will get the inflammatory situation under control.
In my case, with years of experience, my primary and I have settled on 7 days of 40 mg and 7 days of 20 mg for an inflammatory flare in back and joints - it seems to work for me. If not, we repeat once. When my lungs flare (asthma and bronchiectasis) 40 mg for 7 days usually does it. If the flare is in a single joint, a cortisone/lydocaine injection is often the answer.

Different diagnoses, and symptoms, my lead to other courses of the drug - or in other words "your results may vary"
Sue