Psoriasis Flashcards Preview

S2.5 Dermatology > Psoriasis > Flashcards

Flashcards in Psoriasis Deck (10):
1

What is the general appearance of psoriasis? Symptoms/signs

Sharply demarcated erythematous plaque with micaceous scale
Numerous and small, widely disseminated
Can have erythroderma >80% BSA
Nails can have oncholysis, pitting, oil spots
Scalp signs
Koebnor phenomenon, Woronoff's ring

2

What are the risk factors/triggers for psoriasis?

Polygenic dispotion + environmental triggers
35-90% have family history

HLA-CW6 allele > 10x risk
PSORS1-9 susceptibility regions

Infection
Drugs
Trauma
Sunlight

3

How should suspected psoriasis be investigated?

Clinical evaluation
Skin biopsy if atypical

4

What are possible differential diagnoses for psoriasis?

Seborrheic dermatitis
Lichen planus
Mycosis fungoides

(Bowens disease, drug eruption, infection, secondary syphilis, contact dermatitis, extramammary Paget's)

5

What are some subtypes of psoriasis?

Chronic plaque psoriasis
Guttate psoriasis
Palmo-plantar psoriasis/pustulosis
Scalp psoriasis
Nail psoriasis
Flexular/inverse psoriasis
Pustular psoriasis
Erythrodermic psoriasis

6

How is psoriasis treated?

GP
- emollients - cream vs ointments
- soap substitutes
- vitamin D3 analogues
- coal tar creams
- topical steroids with care
- salicylic acid

From dermatology
- crude coal tar
- dithranol
- UVB phototherapy (guttate)
- retinoids - acritretin
- immunosuppression - methotrexate, ciclosporin
- biologics - anti-TNF (etanercept), anti-interleukin (ustekinumab)

7

What management should be given in complications of psoriasis requiring hospital treatment?

Fluid balance
Bloods/IV access
Thick greasy ointment emollients
Monitoring - PASI, DLQI

8

What is the general prognosis for psoriasis?

Good with correct treatment
Men lose 3.5y on average
Women lose 4.4y

9

What is the pathophysiology of psoriasis?

Due to adaptive immune system
- T cells (epidermal CD8, dermal CD4 and 8)
Stressed keratinocytes
Activation of dermal dendritic cells - present uncertain antigen to naive T cells in lymph nodes - differentiation into Th cells > psoriatic dermic and plaque formation
Keratinocyte proliferation
Cell cycle reduced from 28 days to 3-5 days

10

What are the histological features of psoriasis?

Hyperkeratosis - thickening of stratum corneum
Neutrophils in stratum corneum (munro's microabscesses)
Psoriasiform hyperplasia - acanthosis - squamous cell layer thickening with elongated rete ridges
Dilated dermal capillaries
T cell infiltration