Phototyping in Skin of Colour

Skin pigmentation evolved as a protective response in hominids, alongside the loss of body hair. Over the centuries, further migration and adaptive changes resulted in the wide variety of skin colours seen in today’s populace. Most research on skin typing has predominantly been in lighter skin types. It is in recent times that studies, particularly from the LATAM, Africa, and the APAC regions, are shedding light on the unique dermatological needs of SOC individuals, including sunscreen use. Skin phototyping, with the widely used Fitzpatrick scale, focuses on cutaneous reactivity in the form of erythema response to sunlight or UVR. However, despite modifications proposed to accommodate ethnic variations, such as Sharma’s classification in India, challenges persist in accurately assessing skin reactivity, particularly in higher skin types where erythema may not be reliably observed. Alternative classification systems, like the Kawada Skin Classification and Lancer Ethnicity Score, offer insights into specific ethnic groups’ responses to UV exposure. In addition, user-friendly tools, such as the Taylor hue cards, the Felix von Luschen skin colour chart, and Pantone skin tone guide, help in simplifying clinical assessments and can also be used for cosmetic applications, such as obtaining precise matches in colour cosmetics. Recent advancements such as colorimetry and reflectance spectrophotometry provide more objective measures of skin colour and melanin content, bypassing limitations of subjective phototyping based on skin reactivity with its inherent variability. Specifically, the individual typology angle (ITA) is considered an objective approach to skin typing and has been included in recent guidelines for sunscreen testing. However, in vivo sunscreen guidelines do not include testing individuals with the darkest skin tones, which handicap may be overcome by hybrid diffuse reflectance spectroscopy (HDRS).