(edited from the skintherapyletter.com article: Laser Management of Acne Scarring)
Acne is the most common skin disorder seen by doctors. In fact, it will affect almost every one of us at some time in our lives. If not treated properly, acne can leave behind permanent scars.
Scars caused by acne are much more common than doctors once believed, most people will have acne scars that are mild. However, some will have scars that look significant even to others. There are a number of different looking scars caused by acne.
Icepick Scars – These appear as deep pits, and are the most common form of acne scarring.
Box-car Scars: Angular scars that usually occur on the temple and cheeks, and can be either superficial or deep, these are similar to chickenpox scars.
Rolling Scars: Scars that give the skin a wave-like appearance.
Hypertrophic Scars: These appear as raised and thickened (keloid) scars.
Acne scars form when inflammation damages the deeper layers of the skin. Individuals who have severe cases of cystic acne are more prone to developing scars after the acne has gone away. Scarring can also occur for individuals that have mild cases of acne. Picking at, or popping a pimple can injure the skin and lead to permanent skin damage and persistent skin discolorations, such as red and brown spots.
Acne scarring is often challenging to manage. Various laser treatments are helpful in addressing abnormal color and texture in order to improve the appearance of an acne scar. This article will look at the appropriate use of lasers for specific types of acne scarring.
Laser Options Targeting Skin Color
Red Scar Treatment
Erythema (skin redness) is the result of visible blood vessels beneath the skin surface. This is often seen in acne scarring. The intensity of the redness is dependent on the concentration, size, and depth of the blood vessels. Lasers and light sources used to decrease erythema of acne scars include:
- Pulsed Dye Laser
- Intense Pulsed Light
- KTP Laser
- Nd:YAG Laser
Pulsed Dye Lasers are the gold standard for treating skin redness from acne scarring.2 The device works by producing an intense beam of light that is directed at a small area, usually to destroy skin growths. Generally, this is a relatively safe procedure with very little risk of complication. Treatments may be safely performed on all skin types and over hair-bearing areas without fear of causing damage to hair follicles. Purple discolorations can occur as a side effect.
Intense Pulsed Light, often simply called IPL, is not a laser, but a spectrum of light. It can be used to improve both brown and red scars on the face. Intense Pulsed Light therapy uses laser technology to deliver computerized pulses of light to improve skin imperfections caused by acne scars, rosacea, spider veins and flushing. Intense Pulsed Light devices have the benefit of larger spot sizes and a wider range of pulse duration, thereby allowing for treatment at greater depth and faster speed, coverage of larger surface areas, and the simultaneous treatment of multiple conditions. As a side effect, postinflammatory hyperpigmentation in darker skin types may be seen with this treatment.3
The KTP laser is used to treat small caliber skin discoloration caused by acne scars, broken blood vessels, cherry angiomas and spider angiomas. KTP lasers don’t penetrate as deep into the skin and are often used to treat superficial areas of skin discoloration. As a side effect, KTP lasers may cause mild purple discolorations and minimalpost-inflammatory hyperpigmentation.
Nd:YAG lasers may be useful for treating redness in scars with dilated blood vessels that are deep in the skin. The Nd:YAG laser absorbs colored pigments in the skin, so it is used to remove spots of discoloration. One advantage of this laser is that there is no need for anesthesia, and the process is relatively painless. After treatment, the area will become white with some surrounding redness.
Brown Scar Treatment
Hyperpigmentation of acne scars is common, particularly with darker skin types. In many cases this will cause skin discoloration that are brown in color. Lasers used to treat scar hyperpigmentation include:
- Intense Pulsed Light
- Quality-switched Lasers (Q-switched)
- Microsecond-pulsed Nd:YAG
In addition to treating red scars, Intense Pulsed Light is also an effective treatment for brown scars.
Q-switched lasers have the unique ability to target very small pigment cells and particles. These lasers emit intense pulses of light that pass through the upper layers of skin and specifically target the discolored pigments by breaking them up into smaller particles, which are then carried away by scavenger cells of the body’s immune system. 4 Care must be taken to use the lowest energy settings possible to achieve pigment reduction, as too much energy may result in bleeding, cell rupture, scarring, and increased pigmentation.
Microsecond-pulsed Nd:YAG lasers are used to target both melanin pigment and small blood vessels to reduce brown skin discolorations and stimulate collagen production without causing harm to the surrounding tissuse. This laser may be used for any skin type.5
The combined use of lightening creams and sunscreen, as well as sun avoidance, is helpful for further reducing scar color contrast with surrounding skin.
White Scar Treatment
Ultraviolet (UV) light helps improve the appearance of white scars by increasing melanin production in a specific area of the skin. UV light can stimulate the migration of melanin-producing cells to melanocyte-deficient areas, increasing pigment in these areas.1 Excimer Lasers provide concentrated melanin stimulation to white scars.
Fractionated ablative lasers (Er:YAG, YSGG, and carbon dioxide) create air channels that ultimately contract to reduce the surface area of the white scars, making them appear smaller in diameter.7
Laser Options For Targeting Skin Texture
Fractionated ablative lasers (Er:YAG, YSGG, and carbon dioxide lasers) can help soften elevated scars by vaporizing areas of condensed collagen that contribute to the scar’s thickness and firmness.7 These lasers must be used with caution in softening elevated scars because there is a possibility of collateral heat damage that can further thicken and harden the scar tissue.
Depressed (Icepick and Boxcar) Scars
In treating icepick and boxcar scars, the goals are to soften the edges between the indentation and surrounding normal skin, and stimulate collagen production within the depressed area. The types of laser therapy that can help accomplish this are: confluent ablative laser and fractionated ablative laser treatments.
Confluent ablative laser treatments (Er:YAG, YSGG, and carbon dioxide lasers) are effective for resurfacing depressed scars on the face. They work by causing thermal injury to skin, resulting in vaporization, collagen stimulation, and wound repair. Er:YAG lasers are highly effective with reduced residual thermal damage. These devices decrease the occurrence of post-treatment redness, are safe for use on darker skin types, and preferred for superficial atrophic scars due to shorter recovery times. YSGG and carbon dioxide lasers work at higher temperatures, making them more beneficial for deeper scars.
Fractionated ablative laser treatment creates microscopic areas of thermal injury on the skin, causing skin tightening and smoothening, as well as elevation of the floor of depressed scars through collagen growth stimulation.11 This type of treatment is gentler on the skin and is safer for darker skin types.
Depressed (Rolled) Scars
With rolled acne scarring, treatment success depends on the degree to which the skin is bound down at the base of the scar. If the skin contour is tightly tethered, it is advisable to perform surgical excision before other treatments to loosen the surface adhesion and dampen the tethering effect.12
Both confluent and fractionated nonablative laser treatments and fractionated ablative laser therapy may be used for rolled scars. In all cases, it is important for the laser energy to reach deeper layers of the skin in order to stimulate collagen regrowth and weaken tethering adhesions.
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