Unit 4 Dermatology Flashcards
stasis dermatitis
- location: lower leg
- etiology: lower extremity edema
seborrheic dermatitis
- location: scalp
- etiology: malassezia furfur
atopic dermatitis
- location: flexor surfaces
- etiology: filaggrin
- associated with asthma and allergic rhinits
psoriasis
- location: extensor surfaces, may include arthritis
- may be associated with inc. risk of cardiovascular disease
irritant dermatitis
-etiology: common irritants
allergic contact dermatitis
- etiology: common allergens
- delayed hypersensitivity reaction type 4
- dx confirmed with patch testing
ABCDEs
A-asymmetry B-border irregularity C-color variation D-diameter >6mm E-evolution
keratoacanthoma
-subtype of squamous cell cancer
Langerhans Cells
skin cell critical to antigen processing and presentation to lymphocytes in epidermis
fibroblast
skin cell responsible for producing collagen
pruritis
- itch
- specialzed skin receptors: meissners corpuscles
- many triggers
- caused by nerve endings
darker skin color is due to:
differences in packaging and distribution of melanin
pacinian corpusles
- responsible for sensation of fine touch
- onion structure
- located in dermis only
- involved in pressure and vibration
- on genitals
meissners corpusles
- pine cone structure
- involved in fine touch
- dermal epidermal junction
- skin receptor
- on finger tips
eccrine glands
- odorless, watery sweat
- VITAL to thermal regulation
- present on lips, palms, soles, forehead
- acquired disorder: miliaria- blocked sweat ducts
- congenital: anhidrotic ectodermal dysplasia- mutation in EDA gene, poor temp regulation
- watery sweat
apocine glands
- primarily located in axilla
- outgrowths of the upper bulge of PEG
- not functional until puberty
- ex. breast feeding
- sticky sweat
sebaceous glands
- exemplify holocrine gland secretion
- lubricate thick, terminal hairs
- cause acne
leukocytoclastic vascultitis
immune complex mediated
Bowen’s Disease
- squamous cell carcinoma
- linked to HPV infection
melassezia furfur
-associated with: tinea versicolor and seborrheic dermatitis
hemidesmosome
- attach dermis to epidermis
- in basement membrane zone
desomsomes
- cell adhesion between keratinocytes in stratum spinosum
Layers of Epidermis
surface- stratified squamous
- stratum corneum (filagrin connects this layer to other layers)
- stratum lucidum- on hands and feet only
- stratum granulosum- fillagrin cross links keratin filaments and is important in barrier functinon of skin
- stratum spinosum- keratinocytes
- stratum basalis- melanocytes and stem cells (skin color), desmosomes here
- 1 melanocyte: 10 keratinocytes
- 1 melanocyte can provide color to ~30 keratinocytes
- californians like girls (in) string bikinis
Dermis
- papillary
- reticular
- ground structures (assist with perfusion)
- collagen
- elastin
- blood vessels and nerves present
- also blood, nerves, adnexal structures
Fitzpatrick Skin Types
I. Never tans, always burns, freckles
II. Tans with difficulty, usually burns, freckles
III. Average tanning, sometimes burns, freckles
IV. Easily tans, rarely burns
V. Very easy to tan, very rarely burns
VI. Never burns
Melanin Types
- eumelanin- black to brown pigment
- pheomelanin- yellow to red-brown pigment
Skin Pigmentation Differences
Light Skin: melanosomes smaller and distributed in clusters above the nucleus in the keratinocyte
Dark Skin: melanosomes larger and distributed individually
throughout the cytoplasm of the keratinocyte
Flat Morphologies
- macule (<1 cm)
- patch
Raised Smooth Morphology
- papule (<1cm)
- plaque
- cyst
- nodule (1-2cm)
Fluid Filled Morphology
- vessicle (1 cm)
- pustule (pus)
eschar
crust
Tzanck Prep
test for herpes
Solar Elastosis
- acquired elastic disorder
- indicates tissue from older person in sun exposed site
Pseudoxanthoma Elasticum
- congenital elastic disorder
- caused by mutation in MDR gene
- “plucked chicken skin”
acquired disease of ground structure
-cosmetic filler agent
Ehlers Danlos Syndrome
-congenital disorder of collagen
scurvy
-acquired disorder of collagen
disorders of capillary loops
- psoriasis
- verruca
vasculitis
- inflamed blood vessels
- type 3 immune reaction
adnexal structures in dermis
- hair follicle
- eccrine gland- sweat
- apocrine
- apoeccrine
- sebaceous- oil
Hair Cycles
- anagen- growing (3 yrs)
- catagen- involution (3 weeks)
- telogen- resting hair (3 months)
Anagen Effluvium
-loss of growing hair
telgen effluvium
-hairs go into resting cycle
acquired disorders of sweating
- heat shock
- “antipersperant”
apoecrine gland
- hybrid sweat gland
- 10x as much sweat as eccrine gland
actinic keratosis
- most common precancer in US
- turns in SQUAMOUS and basal cell cancers
benign vascular skin tumors
- cherry angioma
- hemangioma
benign vascular malformation (endothelial cells)
-port wine stain
benign sebaceous gland tumors
- sebaceous hyperplasia
- nevus sebaceous
beingn fibroblast tumors
- dermatofibroma
- keloid scars
benign keratinocyte tumor
-seborrheic keratosis (barnacles of life)
benign tumor of melanocyte
nevus
peptides involved in innate immunity of skin
- alpha defensins
- beta defensins
- cathelicidin
- psoriasin
- RNase7
veruca
- means wart
- caused by HPV
KOH test
-detects fungus
aspergillis
lung infection fungus
powder + grease =
-protective pastes
grease + liquid =
- ointments
- creams
- lotions
powder + liquid =
- drying pastes
- gels
- shake suspensions
