Photograph contributed by Robert Aylesworth, M.D.

Cutaneous anthrax usually begins as a small, raised bump that might itch. Within 1 to 2 days, the bump develops into a painless, fluid-filled blister about 1 cm (0.4 in.) to 3 cm (1.2 in.) in diameter. Within 7 to 10 days, the blister has a black center of dying tissue-called an eschar-surrounded by redness and swelling.