Objective, colourimetric scale for assessing skin colour
Objective, colourimetric scale for assessing skin colour
Proposed scale would aid in categorizing skin of colour without reference to race or ethnicity; assist in diagnosis and procedure planning (1,300 words, 6 minutes)
Dermatologists’ use of the Fitzpatrick classification for skin types has been deemed unsuitable for categorizing patients with skin of colour in a recent editorial.
In the commentary by dermatologist Dr. Philip R. Cohen of the University of California, Davis Medical Center and collaborators published in Cureus (Nov. 1, 2023), the authors discuss some of the history of skin type grading systems and propose a six-step colourimetric scale.
“Since 1975, dermatologists have used the Fitzpatrick classification of sun-reactive skin types to categorize patients with skin of colour; this classification was established for psoriasis patients participating in using oral methoxsalen and phototherapy clinical trial to determine the initial ultraviolet A dose,” the authors report. “The Fitzpatrick classification merely classifies individuals as white, brown, and black; the individuals with white skin are further divided into four groups based on their burning or tanning capacity. This classification system does not provide reliable information about the risk of skin cancer for individuals with darker skin colour. It does not aid in the evaluation of medical conditions with cutaneous involvement or assessment of appropriate cosmetic interventions for aesthetic management.”
The authors note that other established scales for skin of colour either include white skin colour, or have 10 or more colour types, or both. The goal of the new scale is to be a simple, rapidly performed scale not based on race or ethnicity that can categorize persons with skin of colour.
The proposed scale ranges from very light beige to very dark brown, based on CMYK values. (CMYK is a system of representing reproducible colours developed for the graphics and printing industries.)
Very light beige Cyan 0%, Magenta 16%, Yellow 33%, Black 16%
Light brown 0%, 25%, 47%, 35%
Medium brown 0%, 36%, 81%, 58%
Dark brown 0%, 34%, 67%, 70%
Very dark brown 0%, 50%, 100%, 80%
An individual with White skin would be a zero on this scale.
“We anticipate that incorporating this colourimetric scale during the assessment of the patient will be a simple, rapidly performed visual examination by the clinician during their evaluation of the person,” the authors note.
They conclude a scale that is not based on race or ethnicity is beneficial for sociologists and clinicians who treat these patients. In addition to helping dermatologists categorize persons with skin of colour to predict their risk for developing skin cancer and assessing appropriate cosmetic procedures and devices, the colorimetric scale will be helpful for forensic pathologists and other clinicians to provide a non-racial and non-ethnic designation of skin colour type, they write.
From the literature on skin type classification
Optimization of skin phototype classification
The authors of this literature review write that understanding individuals’ skin pigmentation and photosensitivity is important in judging the risk of skin cancer and response to specific treatment modalities.
They note that individuals with darkly pigmented skin are poorly represented in the widely used Fitzpatrick skin phototype system. That system is prone to misuse due to its reliance on subjective assessment and lack of clear differentiation between pigmentation and photosensitivity.
The authors examine the literature on the Fitzpatrick skin phototype system, its criticisms and proposed alternatives to understand how skin phototype classification can be optimized.
A genome-wide genetic screen uncovers determinants of human pigmentation
Researchers conducting a genome-wide genetic study identified 169 functionally diverse genes related to melanosome biogenesis, endosomal transport, and gene regulation, of which 135 represented previously unknown associations with pigmentation.
The authors note that, as could be anticipated by their melanin-promoting function, most ‘hits’ in the gene screening were up-regulated in melanocytes from darkly pigmented individuals.
They also identified the functions of Kruppel-like factor 6 (KLF6) as a transcription factor that regulates melanosome maturation and pigmentation in vivo and of the endosomal trafficking protein COMMD3 in modulating melanosomal pH.
In their conclusion, the authors say their findings have broad implications for human variation, cell biology, and medicine.
Evaluating skin colour diversity in the validation of scar assessment tools
In this study, researchers assessed the racial diversity of patients included in the validation of scar assessment scales. They systematically reviewed articles reporting on the validation of a scar assessment tool and extracted racial, ethnic and Fitzpatrick skin type (FST) data.
A total of 15 scar scale validation studies were included. Of those, nine did not mention the patients' FST, race, or ethnicity. Two of the studies that reported FST or race information only included White patients or included no FST V/VI patients. Only four studies included non-White patients or dark-skinned patients in the validation of their scar scale: the modified Vancouver Scar Scale (VSS), modified Patient and Observer Scar Assessment Scale (POSAS), acne QOL and SCAR-Q scales.
The patients included in the modified VSS validation were 7% and 13% FST V/VI, 14% African in the modified POSAS and 4.5% FST V/VI in the SCAR-Q.
In their conclusion, the authors write that including patients of colour in scar scale development will improve scar assessment and clinical decision-making.
A novel method to determine patient skin type: The Skin Analyzer
This paper presents a novel way to measure skin colour from photographs using a desktop application called the Skin Analyzer. The authors suggest this app may be a more effective, accessible, and efficient alternative for gathering skin type data than in-person assessment using dedicated equipment such as spectrophotometry.
The app converts skin samples collected from digital images to the L*a*b colour space and uses those values to calculate an individual typology angle that correlates to a Fitzpatrick skin type.
To assess accuracy in variable lighting, the researchers printed and photographed six known colours representing the six Fitzpatrick skin types in 15 separate locations within a hospital setting.
They calculated interrater reliability with data from 13 untrained users testing the app on six subjects. The accuracy of measuring known values, which is the classification accuracy, was calculated to be 80%. Using the Krippendorff alpha test to evaluate interrater reliability, the authors obtained an alpha of 0.84—indicating a high interrater reliability.
VIDEO: Racial limitations of Fitzpatrick skin types
Dermatologist Dr. Susan C. Taylor, incoming president of the American Academy of Dermatology, discusses the pros and cons of different skin type classification systems. Dr. Taylor is the Director of the Skin of Color Research Fellowship and Vice Chair for Diversity, Equity, and Inclusion at Department of Dermatology, Perelman School of Medicine in Philadelphia.
At the intersection of skin and society
On Nov. 23, 2023, the Canada Black Music Archives (CBMA) launched a digital repository dedicated to preserving and celebrating the rich and diverse musical heritage of Black Canadians.
According to a press release, the CBMA, founded in 2020, aims to fill a gap in Canada’s historical narrative by providing a digital platform accessible to all. This platform will highlight the contributions, stories, and legacies.
In the release, Executive Director Phil Vassell of the CBMA states: “The CBMA stands as a testament to resilience, creativity, and cultural richness, amplifying the voices of Black musicians and redressing historical underrepresentation. CBMA is a crucial step toward fostering understanding, appreciation, and a stronger sense of identity for all Canadians.”
The archive includes an extensive music collection, photographs, interviews, and historical documents.
This week
Nov. 28 is Giving Tuesday in Canada
December is Universal Human Rights Month
Dec. 3 is International Day of Persons with Disabilities
Something to think about in the week ahead . . .
—Ansel Adams, U.S. photographer, 1902 to 1984
Next week
Skin Spectrum Weekly’s 2023 Indigenous Skin Spectrum Summit coverage begins with Dr. Rachel Asiniwasis’s presentation on the highest priorities for Canadian Indigenous skin conditions for researchers, policy-makers, and stakeholders.
If you like Skin Spectrum Weekly, why not check out Chronicle’s other publications, podcasts, and portal?
Established in 1995, The Chronicle of Skin & Allergy is a scientific newspaper providing news and information on practical therapeutics and clinical progress in dermatologic medicine. The latest issue features:
Drs. Irina Turchin (Fredericton, N.B.), Ron Vender (Hamilton, Ont.), and Ashley O’Toole (Peterborough, Ont.) discuss advances in psoriasis treatment.
Dr. Joel DeKoven (Toronto) details the most common contact allergens based on North American Contact Dermatitis Group data.
An essay from Dr. Fabian Rodriguez-Bolanosi (Toronto) submitted to the 2022 Dermatology Industry Taskforce on Inclusion, Diversity and Equity (DiTiDE) short essay contest. Dr. Rodriguez-Bolanosi wrote about his experience working with Black women in the hair clinic.
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