Psoriasis

Question 1

Presentation of psoriasis

Answer 1

Sharpley demarcated erythematous plaque with micaceous scale (red scaley patches)
Numerous small, widely disseminated papules and plaques 
Erythroderma (>80% BSA)
Pustules 
Nails 
- onycholysis 
- pitting
- oil spots 
Scalp 
Koehner phenomenon 
Woronoffs ring

Question 2

Who gets psoriasis?

Answer 2

M = F
20 - 30yrs and 50 - 60 yrs
75% before 40 years

Question 3

What % develops psoriatic arthritis?

Answer 3

5 - 30%

Question 4

Types of psoriasis

Answer 4

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

Question 5

What can guttate psoriasis be trigged by?

Answer 5

Viral or bacterial infections (commonly strep)

Question 6

Who gets guttate psoriasis?

Answer 6

Children

Adolescents

Question 7

What may happen as a consequence of guttate psoriasis?

Answer 7

May resolve or may trigger chronic psoriasis in susceptible individuals

Question 8

What is palmo plantar psoriasis associated with?

Answer 8

Smoking

Sterile inflammatory bone lesions

Question 9

Presentation of scalp psoriasis

Answer 9

Severe dandruff
Spreading onto face
Hyperkeratotic plaques on scalp, extending just beyond hairline onto neck and forehead
Nail pitting

Question 10

What can scalp psoriasis lead to on the affected areas?

Answer 10

Alopecia

Question 11

What is a key feature of flexural/inverse psoriasis?

Answer 11

No/less scale

Question 12

What can trigger flexural/inverse psoriasis?

Answer 12

Localised dermatophyte, candida or bacterial infection

Question 13

Differential diagnosis of flexural/inverse psoriasis

Answer 13

Localised dermatophyte infection
Candida infection
Bacterial infection

Question 14

Presentation of pustular psoriasis

Answer 14

Sterile pustules

Systemic symptoms

Question 15

Causes of pustular psoriasis

Answer 15

Pregnancy
Rapid taper/stop steroids
Hypocalcaemia
Infection

Question 16

What does pustular psoriasis overlap with?

Answer 16

AGEP (pustular drug eruption)

Question 17

What is erythrodermic psoriasis?

Answer 17

History of psoriasis - flare up

> 80% of body surface erythematous with fine scale

Question 18

What is another name for erythrodermic psoriasis?

Answer 18

Red man syndrome

Question 19

Investigations for psoriasis

Answer 19

Clinical

Skin biopsy if atypical

Question 20

Differential diagnosis of psoriasis

Answer 20

Seborrheic dermatitis
Lichen planus
Mycosis fungoides 
Bowens disease
Drug eruption 
Infection 
Secondary syphilis 
Contact dermatitis 
Extramammary pagets

Question 21

What % of psoriasis have FH?

Answer 21

35-90%

Question 22

What genetic mutation can be found in psoriasis?

Answer 22

HLA-Cw6 (chromosome 6)

Question 23

Causes of psoriasis

Answer 23

Genetic
Infection 
Drug
Trauma
Sunlight

Question 24

Pathology of psoriasis

Answer 24

T cells (epidermal CD8, dermal CD4 + CD8)
Stressed keratinocytes
Activation of dermal dendritic cells by interleukins and TNF alpha
dDCs -> lymph nodes, present uncertain antigen to naïve T cells
Differentiation into T helper 1, 17 and 22 -> psoriasis -> plaque formation
Interleukins and TNF alpha amplify the inflammatory cascade, stimulate keratinocyte proliferation
VEGF -> angiogenesis
Neutrophils in acute, active, pustular disease
Cell cycle reduced

Question 25

What is the cell cycle change in psoriasis?

Answer 25

Reduced from 28 days to 3-5

Question 26

Histology of psoriasis

Answer 26

Hyperkeratosis (thickening of strateum corneum) Neutrophils in the strateum corneum Psoriasiform hyperplasia; acanthosis (thickening of squamous cell layer) with elongated rete ridges Dilated dermal capillaries T cell infiltration

Question 27

Treatment of psoriasis

Answer 27

``` Regular Emollients Soap substitutes 1. Vitamin D3 analogues (inhibit epidermal proliferation) + potent corticosterioid once daily 1st line Coal tar creams / crude coal tar Topical steroid (flexures, genitalia) Salicylic acid (keratolytic) Dithranol UVB phototherapy (guttate) Retinoids - Acitretin Methotrexate Ciclosporin Biologic therapies (Anti-TNF etc) ```

Question 28

Treatment of erythrodermic psoriasis

Answer 28

``` Admit Fluid balance Bloods/IV access Thick greasy ointment emollients Possible systemic or biologic treatment ```

Question 29

How is psoriasis progress monitored?

Answer 29

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

Question 30

What does PASI look at?

Answer 30

Surface area Plaque colour Thickness Scale

Question 31

What does DLQI look at?

Answer 31

QOL in last 1 week

Question 32

What prognostic outcomes is psoriasis related to?

Answer 32

``` CVS disease Smoking Metabolic syndrome Alcohol Depression Suicide Melanoma and non melanoma skin cancers Harmful drug and light therapies ```

Question 33

Patients with psoriasis are at increased risk of what?

Answer 33

Arthritis | Cardiovascular disease

Question 34

Complications of psoriasis

Answer 34

Psoriatic arthropathy (10%) Increased incidence of metabolic syndrome Increased incidence of cardiovascular disease Increased incidence of VTE Psychological distress

Question 35

Exacerbating factors of psoriasis

Answer 35

``` Trauma Alcohol Drugs - beta blockers - lithium - antimalarials - NSAIDs - ACE Is - infliximab Withdrawal of systemic steroids ```

Question 36

What drug can make psoriasis worse?

Answer 36

NSAIDs

Question 37

The 5Ps of lichen planus

Answer 37

``` Polygonal Pruritic Planar (flat-topped) Papular lesions Purple ```