Dermatology

Question 1

what is this

Answer 1

EM

symmetrical and acral e.g. on hand, feet and limbs
damaged skin in the centre and are dusky and bullous
heal without scarring
target lesions

Question 1

Most common cause of Erythema Multiforme in children + other causes

Answer 1

HSV

mycoplasma pneumoniae, NSAIDs

Question 2

what is this

Answer 2

Pityriasis rosea

post viral rash
eruption of erythematous plaques, may start with one large red patch with peripheral scaling, followed by widespread eruption of small scaly lesions on the trunk
may be preceeded by a cold
christmas tree pattern
usually not itchy but can be in some cases v itchy
resolves 6-12/52

Question 3

first management step of Epidermolysis bullosa

Answer 3

decompress intact blisters

Question 4

alopecia areata

Answer 4

hair loss well circumscribed
normal scalp
non scarring and non painful
nail pitting
FH

Question 5

Tinea capitis

Answer 5

hair loss with erythema and scaling of the scalp
treated with terbinafine after skin samples have been taken

Question 6

telogen effluvium

Answer 6

sudden increase in hair shedding
3-4 months after event e.g. illness, medications, nutritional deficiency

Question 7

aplasisa cutis

Answer 7

present from birth / genetic
localised absence of skin with poor or no hair growth

Question 8

molluscum contagiosum

Answer 8

poxvirus
flesh coloured dome shaped papules
central umblication
appear in clusters
those with eczema or immunosuppressed may develop large numbers

Question 9

chronic bullous disease of childhood

Answer 9

linear immunoglobulin A disease
age >3
tense small blisters on erythematous background
affect: perianal area, trunk, thighs, limbs, hands and feet, may be mucosal involvement

Question 10

epidermoylsis bullosa

Answer 10

localised to friction sites e.g. hands and feet
tense small blisters
onset: time of walking or crawling

Question 11

pomphylox

Answer 11

sudden onset crops of clear vesicles usually B/L
affects fingers, toes, palms and soles

Question 12

lichen planus

Answer 12

pruritic eruption of unknown aeitology
usual distribution: mouth and flexor aspects of knees, elbows, ankles and wrists
koebner phenomenon: occur at sites of trauma

Question 13

cyproterone acetate for acne works by inhibiting which enzyme

Answer 13

17 alpha hydroxylase

Question 14

mechanism of action of phototherapy

Answer 14

induction of pyrimidine dimerisation

Question 15

toxins associated with staph scolded skin syndrome

Answer 15

Epidermolytic toxins A and B

Question 16

piebaldism

Answer 16

AD
congenital leucoderma
hyperpigmented lesions within the leucoderma (white patched of skin)
hands and feet spared
frontal white forelock

Question 17

Seborrheic dermatitis

Answer 17

presents within first 3 months of life
marked hypopigmentation
resolves by 1
scalp and nappy area affected

Question 18

pemphigus

Answer 18

intra-epidermal bullae
blisters are flaccid and easily punctured

Question 19

keloid scars

Answer 19

excess collagen production e.g. fibroblasts

Question 20

tubersclerosis
TSC1 encodes:
TSC2 encodes:

Answer 20

1: hamartin
2: tuberin

Question 21

Bloom syndrome

Answer 21

AR
growth retardation, photosensitivity, pigment abnormalities and telangiectasia
predisposition to leukaemia and lymphomas

Question 22

Cockayne syndrome

Answer 22

AR
growth failure, progressive neuro deterioration, dental caries, eye abnormalities and sensorineural hearing loss