Dermatology

Question 1

pathophysiology of capillary haemangioma

Answer 1

abnormal regulation of vascular stem cells - comprised of proliferating endothelial cells

Question 2

classification of capillary haemangioma

Answer 2

superficial - upper dermis

deep - lower dermis & subcutaneous tissue

Question 3

stages of a capillary haemangioma

Answer 3

proliferative - over 8-10m

stabilisation - growth plateaus

regression - lesion involutes over a few years

Question 4

Rx of capillary haemangioma if near eye

Answer 4

oral propranolol (only after being seen by opthal)

Question 5

what is morphoea

Answer 5

localised scleroderma

very firm white patches, most commonly thighs, trunk, upper arms

Question 6

what causes a port wine stain

Answer 6

benign capillary proliferation

Question 7

when to suspect sturge weber syndrome if patient has a port wine stain

Answer 7

if it is in the distribution of the 1st branch of the trigeminal nerve

Question 8

presentation sturge weber syndrome

Answer 8

focal epilepsy
LD
glaucoma
stroke-like episodes

Question 9

Ix for sturge weber syndrome

Answer 9

MRI - will show leptominingeal angiomata

Question 10

what is HSP

Answer 10

small vessel non granulomatous vasculitis (IgA mediated)

Question 11

presentation pityriasis rosacea

Answer 11

‘herald patch’ with smaller lesions in a christmas tree distribution (follow the dermatomes)

Question 12

what is erysipelas

Answer 12

a superficial form of cellulitis

Question 13

pathophysiology of eczema

Answer 13

? mutation in filaggrin gene - thought to impair skin barrier function

Question 14

What is seen on histology in eczema

Answer 14

mast cell infiltrates

Question 15

s/e of topical steroids

Answer 15

telangiectasia
thinning of skin&raquo_space; easy bruising
skin atrophy and thinning
striae
localised hypertrichosis
periorifical dermatitis

Question 16

pathophysiology of staphylococcal scalded skin syndrome

Answer 16

exotoxin-mediated epidermolysis (toxins A & B)

disrupt the area between the stratum spinosum and the stratum granulosum, causing blistering of the skin

Question 17

nikolsky’s sign

Answer 17

seen in SSSS

epidermal separation on light pressure with no subsequent scarring

Question 18

pathophysiology of pemphigus

Answer 18

autoantibodies against desmogleins - molecules attaching adjacent epidermal cells together forming part of the desmosome structure

Question 19

most common immunoglobulin subtype in pemphigoid

Answer 19

IgG4

Question 20

what is piebaldism

Answer 20

congenital leucoderma

Question 21

inheritance of piebaldism

Answer 21

AD

Question 22

presentation piebaldism

Answer 22

hyperpigmented macules with normal pigementation within the leucoderma

sparing of hands and feet

Question 23

histological appearance of alopecia areata

Answer 23

T cells within the peribulbar infiltrate

Question 24

pathophysiology of psoriasis

Answer 24

capillary dilatation within the dermis

T cell mediated cytokines causing overproduction of keratinocytes

Question 25

what does a skin biopsy in psoriasis show

Answer 25

acanthosis & parakeratosis

Question 26

Rx psoriasis

Answer 26

1. emollients
2. tar based bath emollients
3. tar and salicylic acid ointments
4. vit d analogues
5. mild potency topical steroid

Question 27

presentation dermatitis herpetiformis

Answer 27

itchy papulovesicular rash symmetrically affecting extensor surfaces + back

Question 28

disease associated with dermatitis herpetiformis

Answer 28

coelaic

Question 29

Ix for dermatitis herpetiformis

Answer 29

anti-transglutaminase blood test - will be +ve for IgA and IgG antibodies

Question 30

ichythosis vulgaris presentation

Answer 30

diffuse and persistent scaliness, white to dirty grey colour

extensor surfaces most common

Question 31

pompholyx presentation

Answer 31

sudden onset of clear vesicles affecting Sides of fingers, toes, palms, soles

Question 32

presentation epidermolysis bullosa

Answer 32

simplex is reserved to sites of friction e.g palms and soles when starts to walk or crawl

Question 33

whitehead aka

Answer 33

closed comedome

Question 34

blackhead aka

Answer 34

open comedome

Question 35

where are melanocytes found

Answer 35

epidermis