Mar 3 - Intro to Dermatology Flashcards
What is the most important form of vit D for humans?
Vit D3
Why is sunlight important in on vit D synthesis pathway?
Converts vit D7 to the usable D3
Pruritis =
itching
Urticaria =
hives
Alopecia areata =
hair loss
What molecule do melanocytes use to protect from UV damage?
Melanin
What is eumelanin?
Good black to brown pigment
What is pheomelanin?
Moderately dysfunctional yellow to brown pigment
You have darker skin if…?
tanning is not the answer
You have more melanocytes more uniformly spread
Vitiligo
Autoimmune disorder that attacks melanocytes - acquired. Complete loss of pigment in effected skin areas
Where are stem cells located in the skin?
Stratum basalis
Which two skin layers do hemidesmosomes connect?
Stratum basalis with stratum spinosum
What two molecules does keratin attach?
Laminins and Type VII collagen
What happens if Pt has an Ab to hemidesmosomes?
Blistering everywhere
What cells do desmosomes connect?
Keratinocytes
What is the most superficial layer of the skin?
Stratum corneum
What skin layer only shows up on tough, thicker skin areas (eg. the palm, plantar foot)
Stratum lucidum
Pemphigus Vulgaris
Flaccid blistering due to an Ab to desmosome proteins. Autoimmune
What are filaggrin and what do they secrete?
They are stretching epidermal cells - secrete Natural Moisturizing Factor (NMF)
What syndrome(s) is/are associated with filaggrin defects?
Icthyosis Vulgaris or Atopic Dermatitis (eczema)
What are langerhans cells important for?
Cell-mediated immunity as Ag-presenting cells – allergies
What are merkel cells?
Cells associated with dermal nerve endings (fine touch)
What are the two layers of the dermis? Which layer contains hair follicles/eccrine glands?
Papillary layer Reticular layer (this one!)
Eschar =
scabs/crusts
Which is smaller, a macule or a patch?
Macule (> 1 cm)
Ecchymosis =
bruise
Bulla =
blister
Pustule =
Pus-filled blister
Erythema =
redness
You see a honey-colored crust. You think this could be:
A bacterial infection
You see a yellow-green crust. You think this could be:
Pseudomonas skin infection
You see grouped vesicles with erythema. You think this could be:
Herpes
You see palpable purpura. You think this could be:
Vasculitis (ex: Leukocytoplastic Vasculitis)
You see a Pt with red skin all over. You think this could be:
Erythroderma - Pt’s are cold all the time
Telangectasia =
Dilated blood vessels close to the skin’s surface
What are some patterns of skin disorder distribution?
Lymphadermic, Dermatomal, Photodistributed (sunburn), Intertriginous (folds), Flexinol (inside elbow/knee)
What does collagen provide the dermis?
Tensile strength
Synthesis of collagen?
Procollagen from fibroblast ->tropocollagen -> aggregation with vitC cofactor
Ehlers-Danlos Syndrome
Genetic collagen disease with poor wound healing and hyperextensible skin/joints
Gorlin;s sign
Being able to touch your nose with your tongue (Ehlers-Danlos Syndrome)
Molluscoid Pseudotumors
Poor wound healing leading to tumor-scars (collagen issue)
What do elastic fibers provide the dermis?
The ability to “snap back” after being stretched
What is Solar Elastos?
Damaged elastic fibers with low resiliency (older Pt’s)
Pseudoxanthoma Elasticum (PXE)
AABC6 gene mut that causes dysfunctional elastic fiber production. Makes skin look like a plucked chicken’s
What does ground substance do?
Allows for diffusion of O2, H2o, nutrients into the epidermis
What is glycosaminoclycan made of/do?
Absorbs H2O - made of hyaluronic acid and dermatan sulfate
Type A dermal nerves
Highly myelinated, quick transduction : touch and proptioception
Type C dermal nerves
Not myelinated, slow transduction: temperature, itching, dull pain
What are Meissner’s Corpuscles?
Natural corpuscles responsible for fine touch (hands and feet)
What are Pacinian Corpuscles?
Natural corpuscles responsible for deep pressure and vibration (genitalia)
What is the embreyonic form of hair?
The Primitive Ectodermal Germ
Three phases of hair growth:
anagen, telogen, catagen (randomly throughout body)
What causes most hair loss?
Testosterone being converted to DHT, causing terminal hair to be converted into vellum hair
What bacterium is responsible for causing acne?
P. acnes
Rosacea is typical for which Pt population?
Middle aged (Celtic) women
Difference between holocrine and eccrine glands?
Holocrine excrete entire cell contents, Eccrine (sweat) glands only secrete a portion of cell contents
Prickly heat is caused by
miliaria = excessive sweating causing blockage of the sweat glands (acquired disorder)
Which glands are responsible for body odor?
Apocrine glands
The glands in the axilla are typically which type?
Apoeccrine glands (mix of apocrine and eccrine - smelly sweat glands)
How do you treat hyperhidosis (too much sweating)?
Botox injections. They block ACh at the secretion plate