How long does acne usually disappear?

Acne marks are dark red pigmentation left after acne has subsided. They are actually delayed erythema caused by dilated capillaries. The speed at which acne marks disappear depends on the individual's physical condition and other factors, such as UV exposure, the size and depth of the acne. The larger and deeper the acne, the more visible the acne marks will be and the longer it will disappear. Some people will gradually disappear in months, but some people will take years or more.