This is a picture of herpes zoster (shingles) on the arm. Shingles are caused by the same virus that causes chickenpox. Outbreaks of shingles follow the distribution of nerves in the skin. This distribution pattern, seen here on the arm, follows a dermatome (see the "dermatomes" picture).
Review Date: 5/30/2012 Reviewed By: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington; and Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.