Dermatitis

Question 1

What is atopic dermatitis?

Answer 1

eczema

Question 2

Which body sites tend to be affected by atopic dermatitis in

a) infants?
b) older children?

Answer 2

a) face and extensor

b) flexor

Question 3

When does 
a) atopic dermatitis
b) asthma
c) hayfever 
typically begin?

Answer 3

a) infancy
b) 2 yr onwards
c) 7 yrs onwards

Question 4

Why does eczema cause pathological infection?

Answer 4

inflammatory cytokines vasodilation causing erythema and leakiness, serum leaks into the tissues causing swelling. Scratching then dries to form a crust which is a culture medium for bacteria

Question 5

What is the most common pathogen found on the skin when it is infected?

Answer 5

staph aureus

Question 6

Give 2 clinical signs of chronic eczema

Answer 6

lichenification

excoriation

Question 7

What are the criteria for diagnosing atopic dermatitis?

Answer 7

itching plus 3 of

• visible flexural rash
• hx of flexural rash
• personal or 1st degree relative with atopy
• dry skin
• onset before age 2

Question 8

What is the itch/scratch cycle?

Answer 8

people scratch itchy skin which damages it so more inflammatory cytokines are released which causes more itching

Question 9

Which protein is deficient in atopic dermatitis?

Answer 9

filaggrin which is a protein essential for allowing keratinocytes to terminally differentiate, if it isnt present then you can’t have an intact skin barrier function

Question 10

Which type of allergic reaction is atopic dermatitis?

Answer 10

delayed type IV

Question 11

What is the difference between an ointment and a cream?

Answer 11

ointments are greasy and oil-based

creams are thinner and water-based

Question 12

How much emollient should be used?

Answer 12

upto 500g/week

Question 13

When should ointments be used?

Answer 13

dry scaly, fissured, lichenified skin

at night

Question 14

When should creams be used?

Answer 14

hot, inflamed, urticated skin

Question 15

How is eczema managed?

Answer 15

emollients 2x day
avoid irritants where possible
topical corticosteroids
cotton clothing
keep cool

Question 16

What is a
a) mild 
b) moderate
c) potent
d) very potent
corticosteroid?

Answer 16

a) hydrocortisone 1%
b) modrasone, clobetasone, butyrate 0.05%
c) elocon betamethasone valerate 0.1%
d) clobetasol proprionate 0.05%

Question 17

What are the side effects of topical corticosteroids?

Answer 17

thinning of the skin
inc skin infections
telangiectasia
acne
systemic absorption is rare --> HPA axis suppression

Question 18

How do corticosteroids work?

Answer 18

1. anti-inflammatory
2. vasoconstrictive
3. anti-proliferative

Question 19

How much does 1 fingertip of emollient weight and cover?

Answer 19

1/2g overs 2 hand areas

Question 20

What is the second line anti-inflammatory treatment used in severe ezema?

Answer 20

calcineurin inhibitors eg. tacrolimus

Question 21

What does eczema herpeticum look like?

Answer 21

monomorphic rash with circular blisters or erosions

Question 22

How is eczema herpeticum treated?

Answer 22

treat with immediate oral or systemic aciclovir

immediate same day referral

Question 23

What is the natural history of mild eczema?

Answer 23

60% clear by adolescence

Question 24

What is the natural history of severe eczema?

Answer 24

most wont clear

2/3rds get hayfever, half get asthma