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.
Review Date 11/1/2019
Updated by: David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 11/01/2019.