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Flashcards in Psoriasis Deck (43)
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1

What is psoriasis and what causes

Chronic autoimmune disease due to hyper proliferation epidermis - keratinocytes and inflammatory cell infiltration
Genetic - HLA B13/17 / FH
Immune
Environment

2

What are environmental relations of psoriasis

Improved sunlight

Worsened
Infection - strep throat
Trauma - Koebner phenomena
Stress
Withdrawal steroid - can cause pustular
IBD
HIV
Alcohol
BB
Lithium
NSAID
ACEI
Quinine

3

What is the pathophysiology of psoriasis

Hyperproliferative epidermis causing abnormal build up and thickening
Stressed keratinocytes (due to trigger) + lymphocytes interact
Activation of dendritic cells by IL + TNF-A
Cause proliferation of keratinocyte + inflammation
Dendritic cells present antigen to T cell
VEGF = Angiogenesis and neovascularisation
T cells and neutrophils infiltrate
Cell cycle reduced from 28 days to 5

4

What is needed to diagnose psoriasis

Neutrophils

5

What does the histology show

Thick stratum corneum = hyperkeratosis
Neutrophils in stratum
Dilated capillaries
T cell infiltration
Psoriasiform hyperplasia

6

What are the 3 types of psoriasis

Type 1 = early onset - 20-30 (most common)
Type 2 = elderly
Type 3 = systemic

7

What is systemic associated with

Psoriatic arthritis = 30% - screen using PEST
CVS disease
VTE
Increased risk of metabolic syndromes
Psychosocial implications

8

What are S+S of psoriasis

Symmetrical
Favour extensor - elbows, knee, scalp
Sharp demarcated erythematous plaque
Silvery scale
Dry
Well defined edge
Raised and rough plaques
Numerous widely disseminated papule and plaque
Can have itch + pain
Nail changes

9

What happens if psoriasis on skin folds e.g. anal area / breast

No scale forms
Can be misDx as yeast infection

10

What are the types of psoriasis

Chronic plaque = most common
Guttate =
Flexural (inverse)
Pustular (palmo-plantar)
Scalp
Nail
Arthritic
Erythrogermic

11

What is chronic plaque psoriasis

Symmetric well demarcated plaques
Silvery scale
Affects extensor surfaces

12

Who is guttate psoriasis common in and what triggers

Children
Viral or bacterial
Typically strep throat 2-4 weeks prior
Raindrop lesions

13

What should you do

Check ASO titre - usually high
Treat if symptmati
No routine use of Ax

14

How does it present and what is outcome

Numerous small psoriatic tear drop lesions / papules
May resolve within 3-4 months
May trigger chronic and turn into plaques

15

How do you Rx

Most resolve
Topical Rx as per psoriasis
YVB

16

How does flexural present

Non scaly and smooth
Often confused with fungal as affects moist areas
Systemic fever

17

What triggers flexural

Dermatophyte / candida
Bacterial
Pregnancy
Withdrawal of steroids
Hypocalcaemia

18

How do you Rx

Combined steroid + anti-fungal to cover

19

How does pustular present

Thick scaly skin on palms and soles
Pustules on hands and feet under skin
Rapid erythema
Systemically unwell - fever / elevated WCC
Koebner

20

How do you Rx

Very resistant
Need to act quickly with systemic Rx
Medical emergency so admit to hospital

21

How does scalp psoriasis present

Pink hyperkeratotoic plaque
Thick adherent scales

22

What can it cause

Alopecia

23

What are nail signs in psoriasis

Pitting = most common
Onycholysis - separation from nail bed
Luekonychia
Oil spots

24

How do you Dx

Clinical or take culture to exclude fungal
Rarely present without psoriasis or arthritis (suggest fungal)

25

What is Koebner phenomenon

Skin lesions / conditions which appear at site of injury or trauma

26

What causes

Psoriasis
Vitiligo
Warts
Lichen sclerosus
Molluscum contagiosa

27

What should you avoid in erthyrodermic psoriasis

Medical emergency = admit
Extensive erythematous area leading to exfoliation
Topical steroid
Can make it turn pustular

28

What is main DDX

Red man syndrome - drug reaction to vancomycin

29

How do you Dx psoriasis

Clinical
Skin biopsy if atypical

30

What are differentials of psoriasis

Seborrheic dermatitis
Lichen planus
Mycosis fungiodes
Bowen's
Drug eruption
Paget's
Contact dermatitis
Secondary syphillis