Chickenpox, also called varicella, is an acute viral disease. It is caused by the varicella-zoster virus. Symptoms include fever, general malaise, and a rash which begins with small reddish bumps (papules) that quickly fill with fluid to form small blisters (vesicles).
Review Date 8/23/2019
Updated by: David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.