The general advice I've seen is to increase the prednisone to the level where you didn't have symptoms. Yes, the decrease from 2 mg to 1.5 mg seems like a small amount. But, in relative terms this is a 25% reduction from the 2 mg dosage. Its the same relative difference as going from 25 mg to 20 mg. Maybe, the body is reacting to that relative change. One of the strategies I've seen is to alternate the 2 mg with the 1.5 mg dosage and then slowly wean down. One rheumatologist recommended a very slow schedule like: 1st week Mon - 2 mg. Tues - 2 mg Wed 1.5 mg Thur - 2 mg Fri. - 2 mg Sat - 2 mg - Sun - 2mg. 2nd week Mon - 2 mg. Tues - 2 mg Wed 1.5 mg Thur - 2 mg Fri. - 1.5 mg Sat - 2 mg - Sun - 2mg. 3rd week - 4 days with 2 mg and 3 days with 1.5 mg. And then you could do the same schedule going down from 1.5 mg. This was in Kate Gilbert's book "Polymyalgia Rheumatica and Giant Cell Arteritis: a survival guide. 2nd edition". Hope this helps and good luck.