Time span for ache from cortisone injection ,in wrist, for arthritis, to disappear? and when will i know if it helped? (had it done yesterday 9/3/15)

Takes a few days: Cortizone (hydrocortisone) injections take a few days to start to work. By two weeks one should know if it has worked and the arthritis pain reduced. At times there is actually an initial increase in pain until the inflammation begins to subside. As long as there is no sign of infection (redness, warmth, fever, a great change in pain) then usually rest and ice can be helpful for the soreness.