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Flashcards in Psoriasis Deck (23)
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1

What is Psoriasis?

Chronic, genetically determined, immune-mediated, inflammatory skin condition, usually characterized by typical well defined, scaly, plaques

Can also involve nails, hair and joints

2

Describe the clinical features of psoriasis?

• Red scaly plaques
• Often symmetrical distribution


• Chronic plaque
• Flexural
• Acute Guttate
• Scalp
• Palmoplantar
• Nail
• Pustular
• Erythrodermic

3

What causes psoriasis?

• Overactivity of the immune system
• Excessive production of TH1 Cytokines inc TNF-alpha
• Vascular proliferation (erythema), increased cell turnover (plaques and scaling)

4

What are precipitants of psoriasis?

• Genetics
• Environmental
• Infection (strep. candida)
• Drugs - Lithium, Beta-blockers, NSAIDS, Steroid withdrawal
• Trauma – Koebner phenomenon (spread with trauma)
• Sunlight (worsens psoriasis in 10% of people)
• Smoking, alcohol and HIV

5

Describe the pathogenesis of psoriasis

Epidermal infiltration by activated T cells
• Increased epidermal cell proliferation and turnover
• Capillary angiogenesis
• Excess TH1 cytokine esp. TNF-a

6

Describe the histology in psoriasis

• Hyperkeratosis (thickening of stratum corneum) with parakeratosis (keratinocytes with nuclei in stratum corneum)
• Neutrophils in strat. corneum
• Hypogranulosis - no granular layer (required for barrier function)
• Psoriasiform hyperplasia: acanthosis (thickening of squamous cell layer) with elongated rete ridges

7

Describe chronic plaque psoriasis

• Scaly plaques on arms, legs and back
• Severe cases with bigger plaques have stronger impact on psycho-social and CVS health
• Commonly managed with topical treatments in primary care setting

8

Describe Guttate Psoriasis

• Acute onset of generalised eruption
• Papules with fine scale - worse on trunk and proximal extremities
• Commonly post-viral
• Self-limiting
• Responds well to phototherapy

9

Describe Palmo-plantar Psoriasis

Skin on the palms and soles appears thick, scaly and red with yellowish brown lesions at the edges

10

Describe scalp psoriasis

Thick hyperkeratotic plaques in the scalp with some pitting of the nails

11

What is differential diagnosis of scalp psoriasis?

Seborhoeic dermatitis

12

What are the features of nail psoriasis?

• Pitting
• Onycholysis (holes/indents)

13

Describe flexural/inverse psoriasis

Shiny pink to red sharply demarcated plaque with no scaling
• Effect areas normally affected by eczema and dermatitis (i.e. armpits)

14

Describe pustular psoriasis

Acute onset of generalised red, tender patches - multiple yellow pustules

15

Describe erythrodermic psoriasis

Generalised erythema of the skin with fine scale
• Red Man’ syndrome
• > 90% body surface area involved
• Needs In-patient treatment

16

How is the diagnosis made?

• Clinical - based on typical presentation
• Skin biopsy if atypical

17

Name three differential diagnoses

• Seborrhoeic dermatitis (esp. scalp, face)
• Lichen planus (check forearm, oral mucosa)
• Mycosis fungicides (older Pt, sudden onset of plaques or treatment resistant plaques)

18

What is the initial treatment?

• Emollients
• Vitamin D3 analogues (calcipotiol) +/- top steroids
• Tar creams
• Topical steroids
• Salicyclic acid

19

What is the second line treatment?

• UVB phototherapy
• Acitretin
• Methotrexate
• Cyclosporin

• Biologics
• Inpatient tar

20

What are the side effects of acitretin?

Teratogenic
Impairment of LFTs/lipids

21

What are the side effected of cyclosporin?

Renal impairment/cancer

22

What is the treatment of erythrodermic psoriasis?

• Admit
• FLUID BALANCE
• Bloods / IV access
• Thick greasy ointment emollients

23

What are is used to monitor psoriasis?

• Psoriasis Area Severity Index (PASI)
• Dermatology Life Quality Index (DLQI)