As skin tries to heal itself, it produces excess collagen to close the wound. Scar tissue contains tough collagen fibers that arrange themselves haphazardly, rather than the even pattern they create regular skin. This distortion of fibers makes them stand out. They often first appear red, then fade over time.

Typically, the longer it takes a scar to heal the worse it will likely look. However, many factors affect how it will appear. Scars located in tight skin stretched over a bone or ones that are indented or raised will stand out more than ones in softer skin or with an even surface.

Scar types include pitted or wavy acne scars; hypertropic scars that are raised and red; keloid scars that are also raised and red but actually extend over the injury, occasionally impairing mobility; and contracture scars, which cause skin tightening and even pain if they affect nerves and muscles. Treatments depend on the kind of scar and its location, but here are some options that may be right for you.

Topical Treatments

Most effective on new scars (you need to wait a few weeks for the wound to heal before applying), they can also help fade older scars.

  • Onion extract, a key ingredient in the popular treatment Merderma, can minimize the appearance of scars but reducing collage production.
  • Silicone gels or sheets have been known help lighten and flatten scars. The exact reason why they work is unknown, but they can help in fading it.
  • Alpha Hydroxy Acids, popular anti-aging ingredients, help exfoliate dead skin cells and improve the appearance of acne scars.

Skin Resurfacing 

Many of the same techniques used for anti-aging treatments can be effective in treating scars.

  • Laser Scar Revision, where strong beams of light help remove damaged skin, is often used to minimize the scar's appearance. Different kinds of scars require different lasers, including carbon dioxide and pulsed dye lasers. It can take a few months for your skin to fully recover from this procedure.
  • Chemical Peels treat scars by removing your skin's top layer, often evening out skin color and removing scar depressions. Recovery times depend on the intensity of the peel.
  • Cortisone injections can soften and even out hard scars, like hypertrophic and keloids.

Soft Tissue Fillers

Designed to fill out a scar depression, these consist of injections of collagen, hyaluronic acid, or even your own fat. While this treatment is not always permanent-- especially with collagen injections--it is simple enough to repeat as needed.

Punch Grafts & Punch Excisions

In a punch graft, a doctor will remove the scar's damaged skin in tiny pieces, replacing these "punches" with normal, unscarred skin taken from somewhere unnoticeable, like behind your ear. These new pieces of skin are taped into place for a week, allowing them to heal. In a punch excision, the damaged skin is removed the same way, then stitched together to heal. Stitches typically stay in for a week. This treatment option is best for pitted acne scars.

Cryosurgery

In order to remove excess tissue, a doctor blasts damaged skin with a freezing agent that causes it to blister and makes it easier to remove.

Sources

Go Ask Alice from Columbia University Medical

http://www.goaskalice.columbia.edu/2534.html

American Academy of Dermatology

http://www.aad.org/public/publications/pamphlets/cosmetic_scar.html