I had chipmunk-cheeks most of my life and I had a bald spot on the back of my head shortly after I started on it, but the WORST side effect was being diagnosed with osteoperosis at 24 years old.
I was already diagnosed with osteoporosis in my mid-20's - I didn't even NEED the prednisone for that lol. They sent me for a dexa-scan after I broke my wrist, since they knew I had a history of kidney disease. And what do you know, they found "frank osteoporosis" in my femeral neck, and low bone density in the lumbar region of the spine.