Scarletred®Vision: A Scalable Digital Solution for Measurement of the Individual Typology Angle (ITA°) and Changes in the Skin Tone

Scarletred®Vision: A Scalable Digital Solution for Measurement of the Individual Typology Angle (ITA°) and Changes in the Skin Tone


SCARLETRED’s mobile technology, Scarletred®Vision, provides clinically validated R&D tools to document, analyse, and monitor skin color and pigmentation variations in multi-centric or home based cosmetics studies.

SCARLETRED’s technology provides a tool for practitioners to document, assess, and monitor skin pigmentation alterations in an objective, standardized, and user- friendly manner.

Skin pigmentation disorders manifest themselves as discolored, blotchy, darker, or lighter than usual skin patches. They occur when the body produces too little or too much melanin, the pigment that creates hair, skin, and eye color and protects the skin by absorbing ultraviolet light, thus providing considerable protection from sun damage (Brenner & Hearing, 2008).

The determination of skin type is fundamental to understanding one's risk for sunburn and, by extension, skin cancer (Skin Cancer Foundation, 2020) and stretches from clinical dermatology to aesthetic cosmetology, reflecting the great importance of having tools for its objective and reproducible assessment.

Individual Typology Angle (ITA°)

The Fitzpatrick scale was initially created for Caucasian skin types and uses subjective parameters regarding erythema and tanning tendencies. Despite its proven limitations, it remains widely used by dermatologists around the world.

To address this issue and create a more reliable and universal measurement tool, the individual typology angle (ITA°) which is based on calculations in the CIELAB color space, more specifically the color parameters L* (Lightness/luminance), b* (yellow/blue), was introduced.

The resulting calculated ITA° classifies skin types into 7 physiologically different categories: very light, light, intermediate, tan, brown, dark and very dark (Figure 1). The difference along the yellow-blue axis (b* parameter), and along the lightness-darkness axis (L* parameter) determine the intensity of skin pigmentation. For an individual with lighter skin color, the ITA° can be expected to be a higher positive value than that of an individual with a darker skin phototype (Figure 1).

Calculated ITA° values have been shown to reflect an individual’s sensitivity to UV radiation and consequently skin sensitivity to sun exposure and skin damage such as pigmentation alterations, cancer, and ageing. From a practical point of view, this translates into determining the type of protection and/or treatments that are most effective on specific skin types.

Scarletred ITA Skin color map and phototype
Figure 1. Individual Typology Angle (ITA°) map. According to their ITA°, individuals are assigned into one of the seven skin classification categories.

The current technological landscape does not offer an adequate scalable method that can be used in a routine medical and clinical setting to enable professionals and experts to determine patients' ITA° and consequently personalize therapy, skin care, and skin protection.

To this end, the digital health company SCARLETRED has developed an innovative solution for the standardized documentation, assessment, quantification, and analysis of skin conditions ranging from dermatological indications to drug reactions affecting the skin: Scarletred®Vision.

Scarletred®Vision is a CE certified Class I Medical Device developed by SCARLETRED. It integrates a clinically validated mobile software core enabling high-quality imaging and documentation of visually perceptible color alterations and provides tools for medical professionals to better visualize and quantify skin color. The technology allows for improved image quality for ITA° assessment as well as sensitivity in comparison to other methods as even minor changes in ITA° can be detected.

The system is ICH-GCP, GDPR- and HIPAA-compliant and is a certified ISO-13485 Quality Management System. It is used in a wide variety of settings, including clinical trials (preclinical to phase IV), routine clinical work, hospital care as well as remote monitoring of patients: Scarletred®Vision’s scalability allows doctors to easily empower their subjects to participate and provide valuable data from the comfort of their home.

How does Scarletred®Vision work?

Scarletred®Vision consists of the following components:

  • Mobile App: generation of high-quality images in conformity with data protection regulations and patient anonymity
  • Skin Patches: calibration of the captured images for color, lighting conditions, and size
  • Online Platform: documentation, assessment, and quantification of patient data

1. Scarletred® Mobile App: Imaging & Questionnaires

Step 1: Place the Skin Patch on the healthy skin next to the area of interest

Step 2: Take an image using the Mobile App, which is then automatically uploaded to the secure online platform

Step 3: The analysis can be performed on the Online Platform, which offers multiple tools to assist the medical professionals

Step 4 (Optional): Questionnaires can also be customized and configured to appear after the image has been taken (Figure 2). The answers and resulting score are documented centrally on the platform together with the subject’s image and the ITA°.  

ITA-Fitzpatrick Classification questionnaire on the ScarleteredVision paltform
ITA-Fitzpatrick Classification questionnaire on the ScarleteredVision paltform
ITA-Fitzpatrick Classification questionnaire on the ScarleteredVision paltform
Figure 2. Scarletred®Vision in-App Questionnaire; The modular software can be configured to have customized questionnaires appear automatically at the interval of choice. In this example, the ITA-Fitzpatrick Classification questionnaire has been configured to automatically appear after an image of the area to be investigated has been captured. Here, the resulting score, which is based on the user’s input, corresponds to the subject’s skin phototype according to the Fitzpatrick Scale.

2. Scarletred® Online Platform: Analysis and ITA° Measurement

The image, taken with the mobile app, is automatically uploaded to the online platform where it can be visualized in multiple signal maps that augment visualization of specific parameters such as erythema. These signal maps are part of SCARLETRED’s proprietary algorithms which are based on the CIELAB color space. This augmented visualization enables the professional to objectively quantify erythema and measure the ITA° at different areas (Figure 3). In order to assess an individual’s skin phototype, the platform executes a number of calculations which results in values for the total number of pixels, mean ITA°, standard deviation, the three dominant colors in the selected area (represented in the Red Green Blue -RGB- color space) and mean RGB (Figure 3). The resulting mean ITA° is the average of the calculated ITA° of each pixel in the area of interest (AOI) over the total number of pixels.

The three dominant colors (in the RGB color-space) are calculated by a clinically validated and proprietary computer vision algorithm from which the mean RGB is derived, representing the overall skin color in the selected AOI.

Furthermore, the Scarletred®Vision Online Platform performs measurements of skin color changes (Delta E, dE) in the AOI over different time points with reference to the baseline (Figure 4). In color science, delta E is a metric used to quantify the distance (or difference) between 2 colors, thereby turning this color change into a reliable metric. This tool gives meaningful insights that can be used in clinical trials and for the assessment and evaluation of treatment or product effectiveness. Moreover, the analytical tools available on the online platform allow the expert to view the calculated data in a scientifically meaningful and descriptive manner and compare the results of different treatments (Figure 4).

ITA measurement of a woman´s cheek on the Scarletered Vision platform
Figure 3. Scarletred®Vision Online Platform: ITA° measurements of an individual’s cheeks in a study for the development of a cosmetic product. First, a reference area is selected (red circle), which represents the person’s native, unaffected skin. In a second step, the areas of interest are selected: in this example, right and left cheek (respectively green and black circles). The measurements result in the following data: mean ITA°, standard deviation, Fold ITA° change between the selected reference area and the AOI, number of pixels, mean RGB as well as the three dominant RGBs for each AOI.

Plot of skin color changes of a woman´s cheek on the Scarletered Vision platform
Figure 4. Scarletred®Vision Online Platform: First, the expert defines a reference area (black circle), which represents the person’s native, unaffected skin and serves as the baseline for the measurement. In a second step, the areas of interest are selected: Delta E (dE, the metric describing skin color changes) is measured on the subject's right cheek (RC, green) and left cheek (LC, blue). The plotted graph shows that the subject´s left cheek undergoes much higher skin color variations than the right cheek. The quantification of the dE uncovers the metric relating to the efficacy of two different treatments applied on the individual’s cheeks.

Scarletred®Vision’s innovative approach to creating digital solutions is the first of its kind. Its modular framework makes it applicable to all skin conditions (dermatological diseases, injection sites, drug reactions, allergic reactions, cosmeceuticals and many more). The certified Medical Device offers digital documentation and analytical tools that have been proven, both in the clinical and home-based settings, to increase data quality, enable doctors to quantify visual parameters, to improve patient treatment regimen and patient compliance, save doctors time, and generate analyses that are not obtainable with other technologies in the field.

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