Simulation of color of port wine stain skin and its dependence on skin variables

The understanding of why Port Wine Stain (PWS) skin is redder and darker as compared to normal skin has so far been based on qualitative analysis. This study aims at quantitatively analyzing the influence of skin anatomy variables on perceived skin color. Reflectance spectra for visible light from normal and Port Wine Stain skin have been calculated using a Monte Carlo algorithm applied to a multi-layered skin model. Skin parameters that were varied are pigmentation, dermal scattering, dermal blood concentration, blood oxygenation, vessel diameter, and vessel depth. The CIE 1976 color system was used to interpret the resulting spectra as colors. A reduced dermal blood content results in a less red and lighter color. Distribution of a constant volume of blood in smaller vessels results in a redder and darker color. Skin with higher dermal scattering was calculated to be yellower and lighter and skin with increased epidermal pigmentation results in a yellower and darker color. Redness of PWS skin depends on both the concentration of dermal blood as well as on how it is distributed