Medical racism and sexism are very real.
One in four residents believe blacks have thicker skin than whites: https://www.pnas.org/doi/abs/10.1073/pnas.1516047113
One in four residents believe blacks have thicker skin than whites: https://www.pnas.org/doi/abs/10.1073/pnas.1516047113
Black people really do have black skin, you know? It's not all racism...
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> There exists substantial evidence to support that Black skin has a higher transepidermal water loss, variable blood vessel reactivity, decreased skin surface pH, and larger mast cell granules compared with White skin. Although some deductions have been made about Asian and Hispanic skin, further evaluation needs to be done. Differences in water content, corneocyte desquamation, elastic recovery/extensibility, lipid content and skin microflora, although statistically significant, are inconclusive.
https://link.springer.com/article/10.2165/00128071-200304120...
> The thickness of the skin is higher on the cheek compared with the dorsal and ventral forearm, with no ethnic or age-related specificity. We confirm that the sub-epidermal non-echogenic band is a sensitive marker of skin aging, and reveal for the first time that it is less pronounced in African Americans. From OCT images, we bring out evidence that the thickness of the dermal–epidermal junction (DEJ) decreased with age, and was higher in African Americans than in Caucasians. Finally, by comparing US images at 150 MHz with OCT images, we show that papillary dermis thickness can be measured and appears to be quite constant irrespective of age or ethnic group.
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1600-0846...
> Skin roughness, scaliness and stratum corneum hydration varied significantly in different anatomic areas and age groups. There was no racial variation in skin hydration between any anatomic site, nor significant differences in roughness and scaliness between races, except for the preauricular area. Skin roughness was significantly increased in the aged, compared to the young at the preauricle, volar forearm, lower back, thigh and lower leg. Older women demonstrated significantly more scaling at the preauricle than younger women. Stratum corneum hydration correlated with scaliness. No significant correlation between stratum corneum hydration and skin roughness was observed.
Blacks age more slowly than whites; Blacks’ nerve endings are less sensitive than whites’; Black people’s blood coagulates more quickly than whites’; Whites have larger brains than blacks; Whites are less susceptible to heart disease than blacks; Blacks are less likely to contract spinal cord diseases; Whites have a better sense of hearing compared with blacks; Blacks’ skin is thicker than whites’; Blacks have denser, stronger bones than whites; Blacks have a more sensitive sense of smell than whites; Whites have a more efficient respiratory system than blacks; Black couples are significantly more fertile than white couples; Whites are less likely to have a stroke than blacks; Blacks are better at detecting movement than whites; Blacks have stronger immune systems than whites
Apparently a majority of white laypeople think that black people literally have thicker skin. Among white first-year medical students, 40% believe this, dropping to 25% of white residents.
Though in the narrow context of skin condition, it is true that people with darker skin “age more slowly”, i.e. have less age-related deterioration in skin quality because they are less susceptible to UV radiation. Minority groups in the USA are also more susceptible to cardiovascular disease, though that’s largely if not entirely attributable to environmental factors.
I don’t know how you’d go about testing some of those and many shouldn’t matter to doctors, but I personally think the differences between us are fascinating.
This isn't really the case because 'races' aren't biologically definable categories, and hence have no direct relevance to evolution. There can be correlations between a person's assigned racial category in a given culture and certain biological features, such as e.g. propensity for sickle cell anaemia. However, this is just because there can be loose correlations between this category (which is usually assigned based on superficial features of appearance and cultural characteristics) and the areas of the world where the person's ancestors hail from. No serious scientific study of human difference pays any attention to race, as it is a largely arbitrary and culturally specific construct.
> the thickness of the dermal–epidermal junction (DEJ) [...] was higher in African Americans than in Caucasians.
There are traits that tend to travel next to each other for historical reasons, as well as because they physically are controlled by the same genes. It's important to pay attention to them; one of the facts that really wrecked the reputation of Kim's Convenience (an anodyne Canadian show I've never watched) was that they gave one of the Korean main characters multiple sclerosis, and Koreans almost never get multiple sclerosis. It made the actress playing the character hate the show.