There is little variation in number of melanocytes between light- and dark-skinned individuals. Skin color is determined by the type of melanin produced and the size and distribution of melanosomes within melanocytes and keratinocytes.
There are several scales and typing systems used to classify patients by skin color. The most commonly used system is the Fitzpatrick skin typing system; however, it does not fully delineate darker-skinned individuals and other systems may be deemed more appropriate for use with skin of color patients.
Stratum corneum thickness appears to be the same across skin types; however, darker skin may be more compact and cohesive. Mast cell granule size has been shown to be larger and ceramides have been shown to be in lower concentration in darker skin.
Data regarding racial differences in lipid content, transepidermal water loss, barrier function, spontaneous corneocyte desquamation, water content and skin irritancy are inconclusive and often contradictory.
Darker pigmented skin provides photoprotective effects including delayed photoaging; however, it also confers greater risk of dyschromia including procedure-related dyschromia.
As the US population continues to grow more ethnically and racially diverse there is an increased interest in skin of color. The practicing dermatologist will need to develop increased awareness of the similarities and differences in skin structure and function in different racial/ethnic groups to better diagnose and treat a diverse patient population.
Interpretation and application of existing data is limited by small sample size, varying methodologies, varying definitions of racial/ethnic groups, and lack of standardization of study protocols. These limitations demonstrate the need for newer studies.
New, large, comprehensive, and standardized studies with clear methodologies and classifications of patients by skin types are currently taking place. These studies will be most useful to address the current limitations seen in this research area.
Skin of color (SOC) describes individuals with increased epidermal pigment and darker skin. This subset of patients has unique cosmetic concerns and often require special consideration for cosmetic procedures. SOC often collectively refers to those of African, Native American, Asian, and Hispanic descents.
There is little variation in the number of epidermal melanocytes between light- and dark-skinned individuals. There are approximately 2000 epidermal melanocytes/mm2 on the head and forearm and 1000 epidermal melanocytes/mm2 on the rest of the body. These differences are present at birth.1 Thus, total number of melanocytes is relatively equivalent among all people.
Melanin is classified into two types: eumelanin and pheomelanin. Eumelanin is darker and exerts a greater photoprotective effect than pheomelanin which is lighter. Eumelanin is characteristically found in darker individuals where it serves as a photoprotectant and free radical scavenger. Pheomelanin is predominantly found in lighter-skinned individuals where it is a less effective UV filter and serves as an endogenous photosensitizer.
Although increased epidermal pigmentation results in a darker skin ...