Color bar tool for skin type self-identification: A cross-sectional study.

The Fitzpatrick Skin Type (FST) has limited relevance and reliability among people with skin of color because individuals from a particular ethnic/racial group cluster into one Fitzpatrick category.1 We developed a color tool to assess skin types. The color bar tool was validated with two cohorts of 120 patients consisting of non-Hispanic Whites (NHW), Hispanics, non-Hispanic Blacks (NHB), and Asians with FST I to VI skin determined by the standard survey. From May to July 2014, a cross-sectional study compared survey responses: color bar tool, skin tone descriptions and the adapted Fitzpatrick skin type questions.2 Participants’ melanin index was obtained using spectrophotometry (Mexameter MX18 probe, Corage + Khazaka Electronic GmbH, Koln, Germany). Sixty self-identified NHWs, 48 Hispanics, and 61 NHBs completed three surveys and had Mexameter readings (n=170). Median age was 50 years old. There were 101 men and 69 women among the respondents. Mean melanin index correlated linearly with the color bar response groups (R2 = 0.965, p < 0.0001), skin tone descriptions (R2 = 0.867, p < 0.0001), and Fitzpatrick sunburn propensity (R2 = 0.879, p < 0.04). For the FST-tan/darker response data, a binomial fit performed best with R2 of 0.963 compared to R2 of 0.236 for a linear model (p = 0.6). Among this ethnically heterogeneous population, people reliably self-selected color bars as assessed by melanin index. Responses to the color bars displayed the strongest linear relationship among the survey items with means evenly covering the range of melanin indices found in our study population. While UVR-related skin cell damage correlates linearly with skin tone, UVR is linked to DNA damage across skin types.3 Race/ethnicity is a poor proxy for skin cancer risk because persons in racial/ethnic minority groups might have individual risk factors for skin cancer (e.g. lighter skin; or skin that sunburns easily). In our research, the colors bars allowed discrimination between the six groups and the colors correlated with melanin index, and with the individual’s potential to have sunburn/skin irritation. Stern4 established that people with FST I, II had a greater skin cancer risk than those with III, IV. Since responses to the adapted FST discriminate among the six categories for all races/ethnicities, Stern’s work can be extended to associating high skin cancer risk with FST I, II; medium risk with FST II, IV and low risk with FST V, VI. As participants understood that survey items either explicitly or implicitly related to their skin color, cultural bias related to a preference for being either lighter or darker may have affected our results. These preferences among different ethnic groups, particularly Blacks, have been well-documented.5 Any attempt to categorize skin cancer risk by skin tone will need to be cognizant of possible shifting subconscious racial biases. Our novel, easily-used color bar tool is economical and does not need a power source, calibration, or processing software, which are needed for spectrophotometry. This tool can be used with limited literacy adults and children, thus, populations can be screened for individuals with skin cancer risk and identify those needing sun protection.