The Asian Dermatologic Patient: Review of Common Pigmentary Disorders and Cutaneous Diseases

Stephanie G.Y. Ho; Henry H.L. Chan

Disclosures

Am J Clin Dermatol. 2009;10(3):153-168. 

In This Article

3. Non-Ablative Skin Rejuvenation in Asians

Non-ablative skin rejuvenation with a laser/light source has gained much popularity in skin of color due to the lower risk of complications and limited downtime.[14] Non-ablative skin rejuvenation involves the use of a laser or light source with a cooling device to improve the signs of photoaging, which include lentigines, telangiectasia, increased pore size, uneven texture, wrinkles, and skin laxity. Cooling is particularly important in skin of color as it protects the epidermis and reduces the risk of erythema and edema, which may lead to subsequent PIH. Green and yellow lasers/light sources (532-nm Nd:YAG, 585- or 595-nm PDL) target the epidermal pigment and papillary dermal vessels. Injury to dermal vessels and microvascular supply of sebaceous glands reduces telangiectasia and sebum production, in addition to promoting new collagen formation during the healing process.[14,52] Near infra-red and infra-red lasers/light sources (1064-nm Nd:YAG, 1320-nm Nd:YAG, 1450-nm diode, 1540-nm erbium:glass) together with a cooling device target water in the dermis and, through photothermolysis, cause a rise in dermal temperature, resulting in collagen tightening and increased collagen production.[4] Monthly treatments are required for a good effect (figure 3).

Figure 3.

Photorejuvenation using non-ablative laser devices: (a) pre-treatment; (b) post-treatment.

More recently, a combination approach that uses different lasers and light sources in the same treatment session at monthly intervals has been advocated.[14,53] This approach targets different skin chromophores and means optimal results can be achieved. When a combination approach is used, a lower fluence should be used for each device to reduce adverse effects due to cumulative heat generation.

Deep-tissue heating using unipolar radiofrequency and newer infra-red light sources affect the deep dermis and achieve enhanced skin tightening. This approach is particularly effective for elevating the eyebrows, treating peri-orbital wrinkles, and contouring the lower face and jawline.[14,54] With effective cooling, the epidermis is protected and PIH is rare even in darker skin types.[55] Unipolar radiofrequency, using multiple passes at a low fluence, is an effective skin-tightening device and results in little discomfort and few complications.[56]

IPL sources that emit radiation in the infra-red spectrum have also been used to achieve deep-tissue heating with subsequent skin tightening. Prolonged exposure with pulse width ranging from 6 to 9 seconds is required to heat up the deep dermis. Contact cooling is again used to protect the epidermis and reduce the risk of PIH.[14]

In patients with more severe degrees of photoaging, fractional resurfacing can be useful for wrinkle and pigment reduction as well as acne scarring. By using a high fluence and low density (15 mJ, 1000 MTZ/cm2), dermal collagen remodeling is induced with minimal epidermal injury. The newer generation of fractional resurfacing laser devices allows for changes in spot size with higher energy and, thereby, permits a greater degree of penetration with a reduction in bulk tissue heating. In skin of color, the principle of minimizing post-treatment erythema in order to reduce the risk of PIH is a useful one. Hence, a reduction in energy and density as well as lengthening of treatment intervals (2-4 weeks for epidermal lesions, 4-6 weeks for dermal lesions) can also be helpful in reducing the risk of PIH.[14]

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