Physiology Sponsored by
Figure 1: Cross section of the epidermis of the skin. Source: Ltd.: London (1999) J Gray, MD. The World of Skin Care, Macmillan Press, showing a melanocyte cell transferring melanin to surrounding keratinocyte cells.
Figure 2: Light reflection and refraction in young skin compared to aging skin.
P&G Beauty & Grooming
Table 1: Current Topical Ingredients for Treating Hyperpigmentation (Source: P&G Beauty Science)
Research shows women want healthy-looking skin, and regardless of where on the color spectrum any one individual is, uniform, even-toned skin is emerging as one of the most critical characteristics of healthy, youthful attractiveness.
In a study conducted by P&G Beauty and two leading evolutionary biologists, Karl Grammer, PhD, and Bernhard Fink, PhD, hyperpigmentation was shown to significantly contribute to the overall appearance of skin aging, just as fine lines and wrinkles do. The study demonstrated that uneven skin tone can add as much as 10 years to an individual’s perceived age.1
As a spa professional, hyperpigmentation may certainly be an area for discussion with many clients, and looking at how skin pigment cells work and learning about some of the technologies that are available to help assess and combat skin discoloration can help you offer better services and treatments.
The epidermis is comprised largely of cells called keratinocytes. Keratinocyte cells are formed at the lowest layer of the epidermis and travel upward, evolving and changing as they migrate and eventually becoming the cells that form the outermost layer of the skin, the stratum corneum.2–3
Melanocytes are specialized cells that reside among the keratinocytes in the lowest layer of the epidermis and have the primary function of producing melanin. The melanocyte packages the melanin into organelles called melanosomes, and then transfers these packets of melanin to the keratinocyte cells. The melanocytes are dendritic, meaning they have a branching structure, similar to the look of a tree.2–3 See Figure 1 for an illustrative explanation.