Acne Scarring
Types
Macules– flat brown, red or purple lesion that forms where a pimple (papule or pustule) used to be. It may remain up to 6 months, but usually fades away.
Postinflammatory Pigmentation– dark spots occurring at the site of a healed inflammatory acne lesion. It occurs more commonly in dark skinned individuals but is occasionally seen in people with white skin. It can take up to 18 months for the pigmentation to disappear.
Scars from increased tissue formation (Hypertrophic or Keloid Scars)– These are red scars that bulge outward resembling lumps. They are due to overproduction of collegen, which is a response of skin cells to a site of injury such as an acne lesion. These scars usually persist over years.
Scars from Loss of Tissue (Atrophic Scars)
These are depressed cavity-like scars due to lack of tissue. This occurs usually occurs when inflammation from acne destroys the skin tissue and the scar tissue pulls the skin down. These scars are similar to those seen in chickenpox): The different types are:
Ice-pick scars– These scare are the most common type usually occurring on the cheeks. They have jagged edges and steep sides- like wounds from an ice pick. They can be shallow or deep.
Depressed Fibrotic Scars– These are large with sharp edges and steep sides. Ice-pick scars may evolve into depressed fibrotic scars over time.
Boxcar Scars– These scars are angular and usually occur on the temple and cheeks. They can be superficial or deep.
Rolling “hill and valley” scars– These scars give the skin a wavelike appearance. They have rolling sloped edges that merge with normal skin.
Causes
The causes of acne scarring are twofold. First, there is injury to the skin caused by the body’s inflammatory response to sebum, bacteria in a plugged hair follicle. Second, is how the body attempts to repair the tissue damage. It may respond by overproduction of collegen resulting in hypertrophic or keloid scars. Alternatively, the tissue can contract and bind down causing the atrophic scars. The incidence of scarring varies considerably between individuals. Some may be more prone to scarring than others. It is difficult to predict who will scar and who will not. Typically, scarring tends to occur in severe nodulocystic acne but can also happen in superficial inflammatory lesions.