INTRODUCTION
Efforts to reduce the burden of skin cancer globally have focused on prevention and early diagnosis. Knowing an individual's skin color and their sensitivity to sun exposure helps with predicting their skin cancer risk.1 The former ways of classifying individuals by broad descriptive categories include skin color (ie, white, brown, and black); race and ethnicity (eg, Japanese or Indian); and response to injury. These classifications are limited and do not adequately categorize the diverse population of the world. Multiple scales have been developed over the years in attempts to better capture the variety of skin colors. Skin color has also been used to predict skin reactivity to insult or injury. Some skin types are more sensitive to allergens and irritants compared with others. Some skin types are more likely to develop hyperpigmentation, hypopigmentation, scarring, and keloids from insult/injury.2 Analyzing skin reactivity is especially important as it enables clinicians to predict an individual’s response to treatments including phototherapy or surgical/cosmetic procedures. While skin color may correlate with certain patterns of skin reactivity, skin color alone is not the sole predictor of adverse effects from dermatologic or cosmetic treatments such as chemical peels or laser treatments. A few newer scales have tried to predict cosmetic outcomes in different skin types. In this article, we propose a modification to the Fitzpatrick skin classification scale that includes skin sensitivity response, based on the common immune signaling pathways between atopic dermatitis (skin sensitivity reaction) and risk factor for keloid formation (response to injury). In addition, we review definitions of skin color, the commonly used Fitzpatrick skin classification scale and other new or modified skin classification systems.
Our Proposal:
Modified Fitzpatrick Scale-Skin Color and Reactivity
Human skin color can be defined on the basis of genetics in the absence of environmental exposures (constitutive) or defined on the basis of exposures to environmental stimuli such as sunlight (facultative).3 Constitutive skin color is determined by a number of chromophores including melanin, hemoglobin, bilirubin, and carotene.4,5 Tools for measuring skin color can be subjective or objective. Subjective tools rely on an individual's self-reported skin color and their response to environmental stimuli such as sun exposure. Objective tools rely on colorimeters and spectrophotometers that measure skin color.
In dermatology, the Fitzpatrick skin classification scale is one of the most common systems used to classify an individual’s skin color. Developed in 1975, the purpose of the Fitzpatrick skin classification scale was to determine the initial ultraviolet A (UVA) dose for people with fair-skin undergoing photo chemotherapy for psoriasis treatment. Later, the scale was expanded to include people with brown and black-skin.6 The Fitzpatrick skin types are classified as I through VI. By constitutive skin color typing, type I through III are considered white, type IV is considered light brown, type V is considered brown, and type VI is considered black. By facultative skin typing, the classification is based on what patients report as their 24-hour reaction to 3 minimal erythema doses (MED) of sun exposure and how much tan developed in 7 days. Skin types I through IV will have responses ranging from "always burn, never tan" to "never burn, always tan."4,6 Skin types V and VI never burn and always tan.
