Atopic Eczema/Dermatitis

Question 1

what is corenification?

Answer 1

loss of the nucleus during differentiation

Question 2

cardinal feature of eczema?

Answer 2

spongiosis
oedema between keratinocytes
inflammatory cell infiltrate

Question 3

what separates types of eczema?

Answer 3

different pathogenic mechanisms

different causes

Question 4

acute eczema phase?

Answer 4

papulovesicular
erythematous lesions
oedema
ooze, scaling and crusting

Question 5

chronic eczema phase?

Answer 5

thickening (lichenification)
elevated plaques
increased scaling

Question 6

is eczema well defined?

Answer 6

no, ill defined

epidermal inflammation

Question 7

what types of eczema/dermatitis cause spongiotics dermatitis?

Answer 7

contact allergic
contact irritant
atopic
photosensitive

Question 8

what types of eczema/dermatitis cause spongiotic dermatitis and eosinophils?

Answer 8

drug related

Question 9

what is lichen simplex dermatitis?

Answer 9

no underlying skin disease
only happens if you scratch the skin enough
causes spongiotic dermatitis and external trauma

Question 10

what is stasis/venous dermatitis?

Answer 10

in people with peripheral oedema

physical trauma to the skin due to hydrostatic pressure causes spongiotic dermatitis and extravasion of RBCs

Question 11

most common contact allergic dermatitis?

Answer 11

nickel

Question 12

feature of contact allergic dermatitis?

Answer 12

often sharp cut off

Question 13

is weeping eczema acute or chronic?

Answer 13

acute

Question 14

why do vesicles/bullae occur in eczema?

Answer 14

acute spongiosis fluid production occurring so rapidly that they form blisters

Question 15

immunopathology of contact allergic dermatitis?

Answer 15

Langerhans cells in epidermis process antigen and then present it to Th cells in dermis
sensitised Th cells migrate into lymphatics and then to regional nodes where antigen presentation is amplified
on next exposure to antigen, sensitised T cells proliferate and migrate to/infiltrate skin causing dermatitis

Question 16

how is contact allergic dermatitis diagnosed?

Answer 16

patch testing

Question 17

contact allergic vs contact irritant?

Answer 17

allergic = specific immune response
irritant = non-specific physical irritation response (not immune)

Question 18

if specific, localised reaction with obvious cause (e.g under a ring)?

Answer 18

often a contact allergic but could be irritant

Question 19

can irritant contact dermatitis overlap with allergic contact?

Answer 19

yes can also overlap with atopic dermatitis

underlying disease makes irritant reaction more severe

Question 20

what implications can dermatitis have?

Answer 20

impact on career choice

Question 21

advise for irritant dermatitis?

Answer 21

create a barrier (e.g gloves)

Question 22

give 5 possible effects of hand dermatitis?

Answer 22

erythema
scaling
fissures
lichenification (thickening of skin)
nail dystrophy
crusting

Question 23

what is nappy rash?

Answer 23

irritant contact dermatitis to urine

Question 24

how can irritant dermatitis and fungal infection be differentiated?

Answer 24

fungal infections tend to favour flexures

dermatitis often has sparing of flexures

Question 25

sign of fillagrin mutation?

Answer 25

increased creasing on hands of children which should be smooth

Question 26

what is the cycle of pruritic?

Answer 26

itch > more scratching > more itchy > more scratching

Question 27

what are the features of atopic eczema?

Answer 27

pruritis ill defined erythema and scaling with generalised dry skin seen most in flexures associated with atopic disease

Question 28

what is fissuring below the ears pathopneumonic of?

Answer 28

atopic eczema

Question 29

what does eczema look like in darker skin?

Answer 29

papular appearance extensive lichenification hypertrophic scarring ill defined erythema and scale still present but less obvious

Question 30

chronic changes in atopic eczema?

Answer 30

lichenification excoriation secondary infection

Question 31

common secondary infection in atopic eczema?

Answer 31

``` staph aureus (golden crusting) atopic people more likely to carry staph aureus rather than epidermidis ```

Question 32

what is eczema herpeticum?

Answer 32

eczema infected with herpes simplex virus | causes monomorphic, punched out lesions all over body (like cold sores)

Question 33

how is eczema herpeticum treated?

Answer 33

a..tivir

Question 34

how is eczema diagnosed?

Answer 34

itch plus 3 or more of: - flexural rash - history of flexural rash - personal history of atopy - dry skin - onset before 2 years old

Question 35

how is eczema treated?

Answer 35

1. emollients 2. avoid irritants 3. topical steroids 4. treat infection 5. phototherapy (UVB) 6. immunosuppresants (azathioprine) 7. biologic agents

Question 36

what causes atopic eczema?

Answer 36

impaired skin barrier function environmental factors immunology possible fillagrin mutation

Question 37

what is discoid eczema?

Answer 37

well defined, circular lesions often get infected patients are often atopic

Question 38

features of photosensitive eczema?

Answer 38

chronic actinic dermatitis clear cut off seen at border of eczema (e.g at collar, sleeves etc) can also be caused by photosensitising drugs

Question 39

what causes stasis eczema and what does it look like?

Answer 39

``` erythema around varicose veins hydrostatic pressure oedema red cell excavation often at ankles ```

Question 40

what is seborrheic dermatitis?

Answer 40

"cradle cap" | atopic eczema on scalp with co-infection with fungus

Question 41

pompholyx eczema?

Answer 41

sudden acute flare of any subtype of eczema with little vesicles (spongiotic)

Question 42

what causes lichen simplex?

Answer 42

normal skin thickening and lesions caused by scratching treated with topical steroids

Question 43

how do you differentiate between allergic and irritant contact dermatitis?

Answer 43

occupational, family and social history | patch testing

Question 44

is pompholyx acute or chronic?

Answer 44

acute

Question 45

can herpes simplex and staph aureus occur together?

Answer 45

yes | punched out lesions with golden crusting