Scars are characterised by marks on the skin which
are left behind after the healing of a burn or other
wound. Scar comes from the Greek word meaning scab.
Scars are also characterised by the fact that they are devoid of any markings on the skin and they do not have any appendages including hair follicles and sweat glands. The skin may be coloured or hyper pigmented.
How do scars form?
The scar reflects how the wounded skin has healed.
Healing of wounds is a dynamic process involving
overlapping phases of inflammation, formation of
granulation tissue and remodelling. The importance
of these different steps of the process depends on
the depth of the lost tissue.
Wounds of a partial thickness only involve the outer layer of the skin and superficial dermis. These kind of wounds exclude any damage to skin appendages including sweat glands, sebaceous glands and sweat glands. These typically heal without any scarring or minimal scarring at worst though in some cases, pigmentation may occur.
Full thickness wounds involving the lower layer of the skin heal with scars. To begin with, there is a clot formation which holds bleeding from damaged blood vessels. This is followed by inflammation and granulation. The edges of the wound start to come together using scar tissue to replace the lost tissue.
The types of scars
Scars can be separated into the two following groups, normal and abnormal scars:
- It is normal for injuries which extend into the deeper layers of the skin (dermis) to result in scars. The scars are typically formed within 10 days after the injury. The wound will continue to undergo remodelling to form a more mature scar over a period of 6 to 12 months. The skin will eventually have about 80% of its original strength.
- Abnormal scars are characterized by excessive scarring to form hypertrophic scars or keloid scars. Abnormal scarring is caused by reasons currently unknown but there are certain factors which can play an important role including size of the wound, the presence of any tension, genetics, skin type and the anatomical location of the scar. Secondary infection, hormonal status and contamination with foreign material can also play a part.
Are lasers able to treat scarring?
Using certain medical lasers, the appearance of
scars can be modified or reduced in many cases. The
pulse dye laser has been used in such treatment for
several years, particularly for raised, red scars.
Depressed scars, such as those often found due to
acne scarring can be treated using fractional
The FRAXEL laser is one of the most effective lasers for treating scars. The FRAXEL works by targeting the skin with laser energy in a pixel like fashion involving penetrating into the deeper skin layers. The FRAXEL laser then promotes the production of more collagen with the aim of blending the scar with the surrounding skin. After a series of treatments, and several months later, scars can be significantly diminished.