Photoprotection in Non-Caucasian Skin

Abstract

To speak about “skin of color” or “non-Caucasian skin” is to address a broadly and inexactly defined group with multiple layers of political and social implications as well as more physiological and biological parameters. For the purposes of this chapter, “skin of color” will refer to those individuals who self-identify as non-Caucasian and whose skin is characterized by a higher melanin content than “white” skin, and whose minimal erythema dose (MED) is, in general, higher than lightly pigmented individuals. Even within the narrow range of “photoprotection in skin of color,” there are a number of considerations in terms of the impact of radiation in the ultraviolet radiation (UVR), visible, and infrared spectra. This chapter will survey several issues relevant to photoprotection for pigmented skin or non-Caucasian populations. In reviewing the development of sunscreens, for example, it becomes clear that these products were developed with Caucasian skin in mind. Sunscreen efficacy is still determined almost exclusively on Caucasian subjects despite growing evidence that subjects of color may differ in complicated ways related to ethnic or racial heritage rather than a simple attenuation of UVR due to melanin. Some of these differences discussed below include rates of DNA repair, the possible contribution of melanin to photodamage, variation in UVR-induced immunosuppression, the risk of postinflammatory hyperpigmentation (PIH) exacerbated by sun exposure, and the potential for vitamin D deficiency in skin of color.