“It’s known for causing these really nasty-looking ulcers—they look like raw meat, beefy and really red, and they have a lot of blood supply so they bleed easily,” says Dr. J. Marrazzo, MD, MPH, chair of the division of infectious diseases at the University of Alabama at Birmingham.
“If they’re left untreated, they really can cause destruction of the tissue around them, which is why people say it’s ‘flesh-eating’ or that it causes skin to ‘rot away,’” Dr. Marrazzo adds. In advanced cases, according to the CDC, the ulcers can spread to the groin, lower abdomen, and upper thighs, and can develop secondary infections of their own.