Pathophys - Atopic Dermatitis

Question 1

true or false

atopic dermatitis is not chronic

Answer 1

FALSE - it is

in remission, it is true that the damage may completely heal and look normal, but the condition is still chronic in that it will always respond to whatever triggered it

Question 2

explain what skin affected by atopic dermatitis will look like

Answer 2

itchy
red
swollen
may crack

Question 3

true or false

in atopic dermatitis, the damage is not very pronounced

Answer 3

TRUE

really just affects the surface of the skin

Question 4

explain some features that can be seen microscopically in atopic dermatitis

Answer 4

epidermal intercellular edema

dermal inflammatory infiltration of leukocytes

endothelial cell hypertrophy

basement membranes thicken

venules altered

increased number of Langerhan’s cells – enhancement of phagocytic cells in skin

hypogranulation of mast cells

Question 5

name 3 things that are contained in mast cells

Answer 5

histamine serotonin heparin – all contribute to the inflammatory process

Question 6

what are langerhan’s cells

Answer 6

fixed macrophages in the skin that are increased in number in cases of atopic dermaitis

Question 7

true or false

skin affected by atopic dermatitis has a much thicker epidermis than healthy skin

Answer 7

true

Question 8

what are corneocytes and how are they related to atopic dermatitis

Answer 8

dead keratinocytes in the stratum corneum (outermost layer of the skin)

these are in a very thick layer in atopic dermatitis

Question 9

what is the relation between atopic dermatitis and genetics?
explain

Answer 9

genetics plays an important role in atopic dermatitis

85% concordance in identical twins

Question 10

name 4 potential causes of atopic dermatitis

Answer 10

genetics
immune system dysfunction
environment
perhaps altered skin permeability

Question 11

how can immune system dysfunction be a potential cause of atopic dermatitis?

Answer 11

the reaction itself is immunogenic (invokes immune system)

Question 12

name 4 ways in which the “environment” can cause atopic dermatitis

Answer 12

chemicals
dry climates
stress
staphylococcus aureus

Question 13

how can staphylococcus aureus cause atopic dermatitis?

Answer 13

when staph colonizes the skin, the barrier function of the skin is impaired. this colonization impairs the microbiome of the skin

we normally have commensal bacteria on skin to prevent overgrowth of more pathogenic organisms like staph aureus on skin.

Question 14

is atopic dermatitis an autoimmune disease

Answer 14

yes

Question 15

true or false

there seems to be a genetic relation in autoimmune disorders

Answer 15

true

Question 16

true or false

staph aureus is not a pathogen

Answer 16

FALSE
it is - can alter and disturb cells in skin – can increase skin permeability

Question 17

as mentioned, altered skin permeability can be a cause of atopic dermatitis. what are some causes of this?
what is the result of altered skin permeability?

Answer 17

could be genetic
could be due to dry climate
colonization of staph aureus
disturbance in fillagrin - disturbs connective tissue
type 4 hypersensitivity

entry of allergens – atopic dermatitis

Question 18

true or false

the skin is virtually impermeable

Answer 18

TRUE

increased permeability due to factors above can lead to entry of allergens/antigens and result in atopic dermatitis

Question 19

what is atopy?

Answer 19

genetic tendency to develop allergy conditions such as atopic dermatitis – exaggerated IgE response to harmless substances

Question 20

___% of people with atopic dermatitis have mutations in gene for fillagrin

Answer 20

30%

Question 21

overall, atopic dermatitis is usually associated with…

Answer 21

INCREASED SKIN PERMEABILITY

Question 22

name the 1 specific gene in which mutations seem to correlate to atopic dermatitis

Answer 22

CARD11 gene

Question 23

what does the CARD11 gene encode for?

Answer 23

the signaling pathway for the development and function of immune cells and lymphocytes

Question 24

how is hygiene related to atopic dermatitis

Answer 24

exposure to some microorganisms, like parasitic infection with helmjinths, actually shows a protective role in preventing AD

Question 25

true or false

children with poor hygiene are at LOWER RISK for developing AD

Answer 25

TRUE

exposure to some microorganisms has actually been shown to protect against AD

also, commensal bacteria on the skin protects from colonization of the skin by staph aureus

Question 26

atopic dermatitis is driven by _______

Answer 26

hypersensitivity - specifically type 1 with a little bit of type 4

Question 27

type ____ hypersensitivity is an anaphylactic reaction

Answer 27

type 1

Question 28

explain the mechanism of type 1 hypersensitivity

Answer 28

IgE - humorl antibody - binds mast cells and they degranulate, releasing a variety of inflammatory mediators such as histamine, serotonin, and heparin – INFLAMMATORY REACTION

upon second exposure to antigen, histamine and other strong vasoactive substances are released

local release causes hives and skin flares, itchy, red skin, while a massive degranulation all over the body will cause systemic anaphylaxis

Question 29

should children be introduced to common allergens earlier or later in life?

Answer 29

earlier

Question 30

what is type 4 hypersensitivity called

Answer 30

cell mediated or delayed hypersensitivity reaction

Question 31

explain how type 4 hypersensitivity is involved with atopic dermatitis

Answer 31

cells migrate to site of antigen
antigens enter and are trapped - lymphocytes pour in and attack the cells to which the antigen is attached

Question 32

poison ivy is a common example of what type of hypersensitivity?

Answer 32

type 4

Question 33

true or false

type 4 hypersensitivity involves antibodies

Answer 33

FALSE - type 1 does - IgE

type 4 involves cells that migrate to site of infection like T cells, NK cells, and macrophages

Question 34

type 4 hypersensisity is regulated by 3 kinds of cells
what are they?

Answer 34

NK cells
T cells
macrophages