OverviewSmallpox is a contagious disease caused by a virus. Smallpox virus has been eradicated worldwide through successful vaccination and treatment programs, and now exists only as a stored virus in a few research centers. Symptoms include a severe rash that leaves scars, fever, headache, vomiting and diarrhea.
Review Date 5/2/2017
Updated by: David L. Swanson, MD, Vice Chair of Medical Dermatology, Associate Professor of Dermatology, Mayo Medical School, Scottsdale, AZ. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.