Dr. Eric Schweiger - MD

Acne Scar Classification

What causes acne scars?

The skin’s response to p. acnes bacteria can produce inflammatory acne (“pimples”), these inflammatory lesions often leave scars behind after they resolve. Some people are more prone to scarring than others, and can end up with disfiguring marks on their skin that do not resolve without treatment. Picking or squeezing active acne can make scarring worse, due to the increased inflammation brought to the area from the act of picking at the pimple.

Are all acne scars the same?

There are different types of acne scarring; it is important to differentiate the types of scarring, as the treatment of each type of scarring is approached differently. There are two main categories of acne scarring, atrophic (meaning loss of skin tissue) and hypertrophic (meaning excessive skin tissue.) Atrophic scars include ice pick scars, boxcar scars and rolling scars; keloid scars are hypertrophic scars.

Ice pick scars

Ice pick scars are very deep and narrow scars with a sharp border. They extend into the dermis and appear as though the skin was pierced with a sharp instrument, such as an ice pick. They may look like an enlarged pore.

Boxcar scars

Boxcar scars are round sunken patches with a steep border. They appear “pitted,” though they are wider than ice pick scars.

Rolling scars

Rolling scars appear as sunken “wavy” areas of the skin, without sharp borders.

Hypertrophic scars

Also known as keloid scars, these appear as firm, raised masses on the skin. Hypertrophic scars are most commonly found of the back and chest, while atrophic scars are much more common on the face.

What is the discoloration left behind after an acne lesion?

Post-inflammatory hyperpigmentation (brown spots) and post-inflammatory erythema (red spots) are marks left behind after the resolution of an inflammatory acne lesion (a “pimple” or cyst.) These marks may improve with time, but often treatments must be used to completely remove these marks. Minor post-inflammatory hyperpigmentation may improve with the use of topical medications such as retinoids or hydroquinone. More significant hyperpigmentation must be addressed with chemical peels or lasers, such as the Fraxel or the Fractional CO2 resurfacing lasers. Minor post-inflammatory erythema may resolve with time, but the improvement may take over a year to appreciate. Many patients with post-inflammatory erythema choose to use lasers, such as the KTP laser, the Fraxel or the Fractional CO2 laser, to see a fast and impressive improvement of the redness left over after acne resolves.

How are acne scars treated?

There are many options available for the treatment of acne scarring. Most atrophic acne scars respond best to resurfacing laser treatments, such as the Fractional CO2 laser using the F.A.S.T technique and the Fraxel laser. Other treatment options for acne scarring include subcision, dermal fillers, punch excision and chemical peels.