Dermatology

Question 1

Describe the lesions in psoriasis

Answer 1

scaly erythmatous well demarcated lesions on extensor surfaces, sacrum and scalp

Question 2

Describe the lesions in guttate psoriasis

Answer 2

frequently triggered by a streptococcal infection. Multiple red, teardrop lesions appear on the body

Question 3

What can exacerbate psoriasis

Answer 3

trauma
alcohol
drugs: beta blockers, lithium, antimalarials (chloroquine and hydroxychloroquine), NSAIDs and ACE inhibitors, infliximab
withdrawal of systemic steroids

Question 4

What are some systemic signs of psoriasis?

Answer 4

pitting nails

arthropathy

Question 5

Describe the stages in treatment of chronic plaque psoriasis

Answer 5

first-line: topical corticosteroid applied once daily plus vitamin D analogue applied once daily (applied separately, one in the morning and the other in the evening) for up to 4 weeks as initial treatment

second-line: if no improvement after 8 weeks then offer a vitamin D analogue twice daily

third-line: if no improvement after 8-12 weeks then offer either: a potent corticosteroid applied twice daily for up to 4 weeks or a coal tar preparation applied once or twice daily

short-acting dithranol can also be used

Question 6

What are the complications of using topical corticosteroids in the treatment of psoriasis?

Answer 6

skin atrophy, striae and rebound symptoms

Question 7

How long is the maximum amount of time corticosteroids should be used in the treatment of psoriasis?

Answer 7

potent corticosteroids for no longer than 8 weeks at a time
very potent corticosteroids for no longer than 4 weeks at a time
aim for a 4 week break before starting another course of topical corticosteroids

Question 8

Give examples of vitamin d analogues

Answer 8

calcipotriol (Dovonex), calcitriol and tacalcitol

Question 9

How do vitamin d analogues work?

Answer 9

reduce cell division and differentiation

they tend to reduce the scale and thickness of plaques but not the erythema

Question 10

Why are vitamin d analogues preferable to corticosteroids or coal tar in the treatment of psoriasis?

Answer 10

adverse effects are uncommon
they may be used long-term unlike steroids
unlike coal tar and dithranol they do not smell or stain

Question 11

What treatments can be used for extensive psoriasis?

Answer 11

phototherapy - UVB 3 times a week

Question 12

What are the adverse effects of phototherapy?

Answer 12

skin ageing, squamous cell cancer (not melanoma)

Question 13

What oral treatments can be used in psoriasis if disease is extensive or systemic?

Answer 13

first line: methotrexate
ciclosporin
systemic retinoids
biological agents: infliximab, etanercept and adalimumab

Question 14

define purpura

Answer 14

red r purple area which does not blanch on pressure

due to bleeding into the skin or mucous membrane

Question 15

define macule

Answer 15

flat area of altered colour

Question 16

define patch

Answer 16

large flat area of altered colour

Question 17

define papule

Answer 17

= solid raised lesion of <0.5cm diameter

Question 18

define nodule

Answer 18

solid raised lesion of >0.5cm diameter with a deeper component

Question 19

define plaque

Answer 19

palpable scaling raised lesion >0.5cm diameter

Question 20

defin vesicle

Answer 20

raised clear fluid filled lesion <0.5cm diameter

Question 21

define bulla

Answer 21

raised clear fluid filled lesion >0.5cm diameter

Question 22

define wheal

Answer 22

transient raised lesion due to dermal oedema

Question 23

define lichenification

Answer 23

well defined rougenign of skin with accentuation of skin markings

Question 24

define crust

Answer 24

rough surface consisting of dried serum, blood, bacteria and cellular debris that has exuded through an eroded epidermis

Question 25

define ulcer

Answer 25

loss of epidermis and dermis

Question 26

define clubbing

Answer 26

loss of angle between posterior nail fold and nail plate

Question 27

define koilonychia

Answer 27

spoon shaped depression of nail plate (anaemia)

Question 28

onycholysis

Answer 28

separation of distal end of nail plate from nail bed (psoriasis)

Question 29

pitting

Answer 29

punctate depression of nail plate

Question 30

state the four layers of the skin

Answer 30

stratum corneum
stratum granulosum
stratum spinosum
stratum basale

Question 31

What is the mechanism behind urticaria

Answer 31

local increase in permeability of capillaries and small venules due to histamine release from mast cells in response to allergen contact

Question 32

what is the difference between uritcaria and angioedema

Answer 32

angioedema is swelling of the dermis and subcutaeous tissues,
uritcaria is swelling of the superficial dermis, which raises the epidermis

Question 33

Describe anyphylaxis

Answer 33

bronchospasm
facial and layngeal odemea
hypotension

Question 34

cellulitis

Answer 34

involves deep subcutaneous tissue

Question 35

What are the suspicious features suggesting malignanct melanoma

Answer 35

Asymmetrical shape
Border irregularity
Colour irregularity
Diameter >6mm
Evolution of lesion
Symptoms - bleeding/itching

Question 36

What are the features of eczema

Answer 36

history of atopy
itchy, erythematous dry scaly patches
face and extensor surfaces in infants, flexor surfaces in children and adultsscratching or rubbing leads to lichenification adn excoriations

Question 37

How is ecsema managed

Answer 37

avoid things that exacerbate
emollients
topical steroids or immunomodulators for flare up
antihistamines for itching

in severe cases wet wraps and oral ciclosporin may be used

Question 38

How should emollients and topical steroids be applied

Answer 38

the emollient should be applied first

wait at least 30 minutes before applying the topical steroid

Question 39

Describe the pathophysiology of psoriasis

Answer 39

chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration