Most scars are caused by either too much tissue formation or a loss of tissue. Atrophic scars fall into this second category, and cause depressions or holes in the skin. This differentiates them from hypertrophic and keloidal scars, whose raised appearances are the result of too much collagen. Acne scars and surgical scars are often atrophic scars, and their sunken formation can signal the loss of muscle or fat that supports the skin. Atrophic macules caused by acne may appear bluish at first because of the blood vessels underneath them but in people with fairer skin, they eventually change to ivory or white and are less noticeable.
Reviewed by: Michael Fuller, MD