@ingekunga, A collagen peptide supplement may help with the skin and hair side effects. My wife and I both take a tablespoon mixed with water or any beverage daily. It dissolves easily and is tasteless. It has fixed the brittle fingernails for both of us and is also good for skin, joints and hair. I would discuss it with your doctor first. I was on prednisone for 3-1/2 years the first round with PMR and 1-1/2 years the second time around. I was always concerned with my skin being thin and easily bruised.

Here's some more information:
Daily oral supplementation with collagen peptides combined with vitamins and other bioactive compounds improves skin elasticity and has a beneficial effect on joint and general wellbeing: https://www.sciencedirect.com/science/article/abs/pii/S0271531717311508