Commonly, the mild type of acne occurring in most people does not leave scars, or if it does, the scarring fades naturally over time. But people suffering from severe forms of acne such as nodular cystic acne might be left with deep scarring in the skin.

There are also marks and pigmentation that relate to acne that are not exactly scars but resemble them physically. These disappear eventually but are evident enough to cause embarrassment. Macules are like pseudo- scars, which are usually left behind by an inflamed acne lesion. These flat red spots are nothing but the last stage of any inflamed lesion. Unlike a scar, a macule might take time to fade, but once it vanishes, it leaves no marks behind.

A discoloration of the skin my occur after the healing of any inflamed acne lesion. It is more usual in dark skinned people, but might occur in white skin also. This is called "post inflammatory pigmentation." It may require treatment by a dermatologist.

Treatment options for scar varieties

According to the shape of tissue, acne scars are classified in two categories. One type of scar consists of augmented skin tissue, and the others are specified by the decrease in tissue on the site of acne. Overgrowth of scar tissue is known as Keloid and is more pronounced in African-Americans. The deep, linear scar formed by acne is called the ice-pick scar. These are very deep and removal of them is difficult.

Another cause of acne scarring is the picking and squeezing of acne. This expands the infection to nearby skin and harms weakened tissue, which results in pit-like scars.

Treatment of acne scars ranges from simple acne scar cream to laser treatment, skin graft, and painful dermabrasion. Filling agents are also applied to remove acne scars. Most filling agents are temporary, like collagen. For deep ice-pick scars, the most appropriate treatment is to cut the scars and replace them with a skin graft taken from behind the ear. This technique is called punch grafting.

Dermabrasion is virtually the opposite of the cutting down technique. Here, the healthy skin is removed to bring the acne scar to a lower level. This way the scar remains the same but the level of rest of the skin changes, making them shallower. It confers skin a softer surface.

In acne scar treatment, another method is laser surgery. In this treatment, carbon dioxide is applied, which eliminates skin very finely, layer by layer, thus reducing the damage to healthy tissue. Like dermabrasion, this method also leaves skin red for months.

In peeling treatments, chemicals are used to remove the external layer of skin, the epidermis. To diminish different types of scars, superficial peels, medium-depth peels, and deep peels are used. These are mostly helpful for shallow, external scars. Scars left by cystic acne and acne rosacea are treated by this method. Peeling is a long process that needs a preparation period of many weeks before the actual procedure.