Dermatology Flashcards
What is “Skin of Color”
Pigmented Skin
What are the racial/ethnic groups that are considered to have “Skin of Color”?
People of African Diaspora
American Indians/Alaskan Natives
Asians and Pacific Islanders
Hispanics and Latinos
Why study skin of color?
1) the mid 21st century, people with skin of color will constitute the majority of the population of the U.S. (No racial or ethnic majority group)
2) increased recognition of health disparities in cutaneous diseases in patients from different racial/ethnic groups
3) Improve understanding of the fundamental differences in the structure and function of skin of color
4) Create novel and/or improved therapies that take skin pigmentation and cultural preferences into account
5) Include this topic in dermatology educational curricula
Studying skin of color allows us to see differences in what?
- Phenotypic expression
- Clinical course/response to treatment
- Outcomes
Why do differences in Phenotypic expression, Clinical course/response to treatment,
Outcomes exist?
- Biological factors
- Socioeconomic factors
- Behavioral factors
- Likely a combination of factors
What is all the same in all races?
The structure and function of skin
What are differences in skin between races?
- Pigmentation
- Hair structure
- Skin aging
- Fibrosis
- Differences in predisposition to specific dermatologic diseases
- Differences in clinical presentation
- The contribution of environment and cultural practices
What is the one feature that is unique to skin of color?
PIGMENTATION
T/F
The number of melanocytes is different in different races / skin pigmentation
False
The number of melanocytes is generally constant regardless of race / skin pigmentation
Racial differences in constitutive skin color are due to?
The amount and distribution of melanin in the skin
What regulates the amount and distribution of melanin in the skin?
Melanosome Number, size, composition, and distribution/aggregation
What does melanin do?
absorbs UV radiation and provides photoprotection
What is the natural SPF for dark skin individuals?
SPF 13
accomplished by melanin
What are the two types of melanin?
Eumelanin
Pheomelanin
What is Eumelanin?
brown/black pigmentation
Where is Eumelanin found?
- Found in all skin types but more abundant in people with dark skin
- Found in grey, black, blonde, and brown hair (except red hair)
What is Pheomelanin?
Red/yellow pigmentation
Where is Pheomelanin found?
- Found in light and dark skin but most abundant in people with red hair
- Particularly concentrated in the lips, nipples, glans penis, and vagina
- Women > men
What is particularly different about Pheomelanin that is not a concern of eumelanin?
Pheomelanin produces oxygen radicals (carcinogenic) when exposed to UV radiation
What is an epidermal melanin unit?
The association of a melanocyte with approximately 30-40 surrounding keratinocytes to which it transfers melanosomes.
Where does all the action happen between the melanocytes and the keratinocytes.
Basal Layer
What are melanosomes?
Organelle within which melanin pigments are synthesized
- Matrix proteins (scaffolding)
- Biosynthetic enzymes (Tyrosinase)
What are the 4 stages to melanosome development?
- Spherical, no melanin deposition
- Oval, obvious metric in the form of parallel longitudinal filaments; minimal deposition of melanin; high tyrosinase activity
- Oval; moderate deposition of melanin; high tyrosinase activity
- Oval; heavy deposition of melanin; electro-opaque; Oval; minimum tyrosinase activity
How do Melanosomes migrate?
Migrate via microtubules into the dendrites in preparation of transfer into the neighboring keratinocytes