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

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


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

In This Article

1. Photoaging in Asians

Ninety-five percent of the visible signs of aging are caused by sun exposure, which begins in infancy and continues throughout life. Other intrinsic factors such as gravity and pollution also contribute to the cutaneous aging process.[4]

Skin of color is differentiated by the amount and epidermal distribution of melanin. Szabo[5] established that although there are no racial differences in melanocyte density, darker skin has larger melanocytes producing more melanin and the melanosomes are distributed individually in keratinocytes. The increased melanin and more dispersed melanosomes appear to absorb and deflect UV light more efficiently, conferring significant photoprotection to skin of color.[6] Tadokoro et al.[7] confirmed this by showing a close inverse correlation between melanin content in the skin and the amount of DNA damage resulting from a given dose of UV radiation.

Despite this, Kotrajaras and Kligman[8] reported that significant photodamage in the form of epidermal atypia and atrophy, dermal collagen and elastin damage, and pigmentary disorders can occur in skin of color. Other investigators have similarly observed that pigmentary changes occur with a greater incidence than skin wrinkling in Asians.[9,10] Chung[11] more recently found both pigmentary changes and wrinkling to be major features of photoaging in Asians. However, moderate-to-severe wrinkling becomes apparent only at about 50 years of age, which is a decade or two later than in age-matched Caucasians.[4]

Other cutaneous manifestations of aging ethnic skin include the development of benign cutaneous growths such as dermatosis papulosa nigra, seborrheic keratoses, and the development of solar lentigines.[4,11]