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Flashcards in Dermatology Deck (67):
1

5 layers of the epidermis

stratum corneum
stratum lucidum
stratum granulosum
stratum spinosum
statum basalis

2

Californians Like Girls in String Bikinis

corneum
lucidum
granulosum
spinosum
basalis
5 layers of the epidermis

3

stratum corneum

top layer of skin
constantly sloughed off
composed of keratin filled a nucleate cells
calluses: stratum corneum hypertrophy

4

stratum basalis

stem cells of skin

5

basement membrane

separates stratum basal is from underlying connective tissue of the dermis

6

epithelial cell junctions

zona occudens
zona adherens
- most superficial junctions

7

zone occludens

tight junctions
prevent diffusion across paracellular space
composition =
claudine = adhesive proteins
occludins = blocks diffusion between cells

8

zone adherens

intermediate junctions - lie just below the tight junctions
cadherins = connect epithelial cells by binding acting filaments in each cell

9

cadherins

Ca-dependent adhesion molecules

10

macula adherens

desmosome
most important
composed of cadherins
connect the intracellular intermediate filaments of adjacent cells
Desmoplakin attaches to the intermediate filaments

11

pemphigus vulgaris

auto-antibodies developed against the desmosome
epithelial sloughing

12

Gap junctions

open channels which allow electric and metabolic communication between two cells
composed of connexons - central channel that allows flow between cells

13

hemidesmosomes

connect cells to underlying cell matrix
use integrins

14

Bullous pemphigoid

auto-antibodies developed against hemidesmosomes (which connect epithelial cell layer to basal lamina basement membrane)

15

Integrin

protein molecules used by hemidesmosomes to connect epithelial cells to the extracellular matrix

16

macule

flat discoloration < 1 cm

17

patch

flat discoloration > 1 cm

18

papule

raised skin lesion < 1 cm
ex: acne vulgaris

19

plaque

raised skin lesion > 1 cm
ex: psoriasis

20

vesicles

small fluid filled blister < 1 cm
ex: chickenpox or herpes

21

wheal

transient vesicles
ex: hives

22

bulla

large fluid filled vesicle > 1cm

23

keloid

abnormal scar tissue hypertrophy that occurs at a site of injury
common in AAs

24

pustules

blister containing pus

25

crust

dried exudate from a vesicle or bulla
ex: chickenpox or impetigo

26

hyperkeratosis

increased thickness of stratum corneum
ex: calluses

27

parakeratosis

hyperkeratosis with retention of nuclei in stratum corneum
ex: psoriasis

28

acantholysis

separation of epidermal cells from one another
ex: pemphigus vulgaris (desmosome auto-antibodies)

29

acanthosis

epidermal hyperplasia (increased # of cells in the spinosum layer of the epithelium)

30

dermatitis

inflammation of the skin

31

verrucae

common warts
HPV common cause

32

nevus

common mole
nevocellular nevus = most common benign mole

33

blue nevus

intradermal, blue color, congenital

34

spitz nevus

benign
juvenile melinoma due to spindle cells

35

dysplastic nevus

develops atypical cells

36

urticaria

common hives
intensely pruitic wheals
mast cell degranulation and histamine release

37

atopic dermatitis

eczema
flexures of skin surfaces
associated with other atopic disorders (asmtha or allergies)

38

allergic contact dermatitis

Type IV hypersensitivity reaction
T-cell mediated reaction following contact with allergens (poison ivy)
acute = ulcers and vesicles
chronic = skin thickening or lichenification

39

psoriasis

autoimmune condition
papules and plaques with silvery scaling
histology:
-parakeratonic scaling = nuclei present in stratum corneum
-acanthosis
-increase stratum spinosum layer
-decrease stratum granulosum layer
Auspitz sign = scraping causes bleeding
association with arthritis and nail pitting

40

seborrheic keratosis

benign, fat, greasy, pigmented lesions
blown scaly, "pasted on" appearance
appear on the head or trunk
histo: epithelial proliferation with keratin-filled cysts
epi: common in elderly

41

albinism

decreased melanin production
histo: normal # of melanocytes
etiology
1. inherited defect of tyrosinase = inability to produce melonin
2. failure of neural crest cell migration during development

42

occular albinism

x-linked disorder
albinism limited to eyes

43

oculocutaneous albinism

eyes, skin, hair = no melanin
increased risk skin cancer

44

vitiligo

autoimmune attack on melanocytes
decreased melanin production
PE: whit pigmented lesions throughout the body

45

melasma (chloasma)

skin hyper pigmentation
commonly seen in pregnancy or OCP use
on face

46

impetigo

infection of superficial skin
highly contagious
etiology: Staph aureus or Strep pyogens
PE: honey-colored crusting

47

cellulitis

acute infection of dermis and subcutaneous tissue = only involves superficial skin layers
etiology: staph or step
PE: erythema, warm, pain, induration

48

necrotizing fasciitis

flesh-eating bacteria
acute infection of the fascia and muscle
etiology:
anaerobes (GI - Clostridium perfringens)
Toxin-producing bacteria (Step pyogenes)
PE: crepitus due to methane and CO2 production
Dark purple looking mottled and painful skin lesions

49

Staphylococcal scalded skin syndrome

exotoxin-producing strain of staphylococcus
histo: destroys keratinocyte attachments of stratum granulosum
PE: skin exfoliation
fever and erythema filled weeks later by sloughing of the upper epidermis
epi: newborns and children

50

hairy leukoplakia

seen in HIV patients
etiology: Epstein-Barr virus
PE: white, painless plaques
found on bottom and sides of the tongue
cannot be scaled off

51

pemphigus vulgaris

IgG Abs against desmosomes
weakened intraepithelial connections
histo: epithelial cell sloughing
immunofluorescence shows reticular, lace-like pattern of antibody surrounded by epithelial cells
PE: positive Nikolsky's sign = manual pressure or movement of the skin causes sloughing
skin and mucosal involvement

52

bullous pemphigoid

less severe phenotype compared to pemphigus vulgarism
IgG antibodies against hemidesmosomes
immunofluorescence = linear pattern following basement membrane
negative Nikolsky's sign
skin involvement - no mucosal involvement

53

dermatitis herpetiformis

ass. with Celiac disease; resembles a herpes infection
IgA Abs at dermal papillae tips
histo: immunofluorescence shows linear pattern Abs aligning epithelial BM
PE: pruitic papules and vesicles
extensor surfaces (ex: elbow extensor surfaces)

54

erythema multiforme

autoimmune reaction seen in:
mycoplasma
herpes simplex
drugs = sulfa, beta lactam ABX, phenytoin
cancers
autoimmune disease
PE: targitoid lesions = red papules with pale central area "bull's eye"

55

Stevens-Johnsons Syndrome

drug reaction
high mortality rate
PE: fever
sever bulla formation
necrosis and skin sloughing
mucosal involvement (ex: oral and genital)
< 30% body involved

56

toxic epidermal necrolysis (TEN)

more severe SJS
> 30% of body surface area involved

57

Lichen planus

pruritic
purple
polygonal = different shapes
papules
ass. with Hep C
histo: saw-tooth appearing T cell infiltrated of epidermal-dermal junciton

58

actinic keratosis

premalignant lesion (precursor to squamous cell carcinoma) - skin
elderly, long term sun exposure (ear, scalp)
damages elastic fibers (changing color in stained tissue to blue gray) of the superficial dermis

59

acanthosis nigricans

hyperpigmented, thick velvety appearance
common on underarms and neck
ass: hyperinsulinemia (T2DM -insulin resistance), viscerlal malignancies (GI cancer)
histo: epithelial hyperplasia of stratum spinosum, atypical basal cells in epidermis, thickened stratum corneum with thinning of the rest of the epidermis, solar damage to dermal elastic fibers

60

erythema nodosum

inflammatory lesion of subcutaneous fat
ass with infections and autoimmune disease
-coccidioidomycosis - fungal
-histoplasmosis- fungal
-tuberculosis - mycobacterial
-leprosy - mycobacterial
-streptococcal infections
-sarcoidosis - autoimmune
PE: common on anterior shins, painful nodules

61

pityriasis rosea

common benign condition
PE: circular herald patch on trunk appears before general rash eruption
Christmas tree pattern rash on the chest, shoulder and back
macules and papules
remits spontaneously - doesn't require treatment

62

strawberry hemangioma

appears in first few weeks of life
large, bright red lesion of the face
spontaneous regression by 5-8 yrs old
arteriovenous malformations

63

cherry hemangioma

common in elderly
smaller than strawberry hemangioma
benign lesion - occur with aging
PE: found all over body, do not regress

64

squamous cell carcinoma

associated with lifetime sun exposure, arsenic exposure and liver angiosarcoma
rarely metastasize
locally invasive
PE: actinic keratosis precursor
erythematous, ulcerated appearance
common on lower face
histo: keratin pearls (squamous cell cancer)
Tx: surgical removal

65

basal cell carcinoma

ass with chronic sun exposure
PE: rolled edges with central umbillication/clearing
pearly papule appearance
telangiectasias overlying papules = small vascular malformations - on surface of papules
common on upper face
histo: palisading nuclei (lined up)

66

melanoma

most likely to metastasize skin cancer
chronic sun exposure
risks: fair skin, dysplastic nevus
PE: large, dark, multicolored lesion with irregular borders
post resection follow up with tumor marker S-100

67

malignant melanoma

asymmetry
border irregularity
different colors
diameter > 0.6 cm