Cystic acne, or nodulocystic acne, is the most severe form of acne. Both pustules and red bumps are present in the skin and scarring can be seen. The back is a common site for acne. Update Date: 04/14/2008Michael Lehrer, M.D., Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.