Cutaneous anthrax is an infection of the skin caused by the bacterium Bacillus anthracis. The bacteria causes disease when it comes into contact with non-intact skin. During an infection, an initial skin lesion forms then blisters. The blister breaks down into a black ulcer and nearby lymph nodes may become infected and painful. A scar is often formed which then dries and falls off within two weeks. In 20% of untreated individuals, the infection may spread to the bloodstream and become fatal. Although with proper treatment, death is extremely rare.
Review Date 5/10/2019
Updated by: 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, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.