Acne frequently occurs on the back. Here, there are 2 to 6 millimeter wide erythematous (red) pustules with large open and closed comedones. Permanent scarring may follow a severe case of acne. Men are more often affected on their shoulders and back than are women.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.