Exposure to cutaneous anthrax can cause a black eschar to form on the skin. An eschar is a piece of dead tissue that can form on the skin and will then be sloughed off. Eschars often form after a burn, a spider bite, or gangrene. The anthrax eschar is painful and will form after an anthrax ulcer is present. The black eschar will usually form within 7-10 days and can last 7-14 days.
