Hi John,
I had terrible Acne in my teenage years (was on prescription meds all through school) but thankfully haven't had that side-effect with my pred. (phew!). I still use Acne solutions foaming wash by clinique and would HIGHLY recommend it! I used Tersaseptic (a shampoo/body wash for acne prone skin) at my worst and still found the clinique as helpful and not as drying. The Tersaseptic was great for my back though - you should be able to get it at any drugstore or chemist)! Clinique does a clear spot treatment gel too which is good for big spots on the face. I hope you find something that works for you! I know how much acne sucks!
Take care,
Kathy