Psoriasis

Question 1

What are the features of classic chronic plaque psoriasis?

Answer 1

• Scaly, red plaques with silvery scale
• Affects buttocks, extensor surfaces, knees, elbows, scalp, ears
• Erythematous red base
• Plaque bc proper step up in skin
• If pick off some of the silvery scale get Auspitz sign which gives pinpoint bleeding
• Can be itchy and painful

Question 2

What are the nail changes in psoriasis?

Answer 2

1) Nail pitting
2) Salmon patches - yellow oily discolouration of nails
3) Onycholysis - serration of nail from nailbed
4) Subungual hyperkeratosis - thickening of the skin underneath the nails
5) Brittle and painful fingernails

Question 3

Describe guttate psoriasis

Answer 3

• Rain drop plaques of psoriasis
• Classically presents a few weeks after strep throat infection (trigger)
• Respond v well to light treatments

Question 4

Describe inverse psoriasis

Answer 4

• No classical scaly features
• Red, shiny rash
• Well demarcated
• Can be confused with intertrigo - bacterial/fungal infection in creases, sweaty, moist areas in skin

Question 5

Describe flexural psoriasis

Answer 5

• Red, shiny rash in flexural areas e.g. armpit
• Less scale bc moist area
• Scaly around the edge where it is less moist
• V well demarcated

Question 6

Describe genital psoriasis

Answer 6

• May lack scale, moister area
• Significant impact on QoL, sexual function
• Misdiagnosed as fungal infection e.g. candida, incorrect treatments, need to recognise it and treat early
• Patient concern re topical steroids in this area - always ask patient if psoriasis affects this area

Question 7

Describe scalp psoriasis

Answer 7

• Cap of scale on scalp
• Associated hair loss
• When treat psoriasis well, hair does generally grow back quite normally

Question 8

Describe photo-aggravated psoriasis

Answer 8

Red rash only where has been exposed to sun

Question 9

Why is photo-aggravated psoriasis unusual?

Answer 9

Bc mostly psoriasis gets a lot better in the sun and is treated with UV treatments

Question 10

What is the Kobner phenomenon?

Answer 10

• Rash tracking in sites of trauma e.g. to scars or where skin has been traumatised in anyway
• Psoriasis comes up in these areas
• Also seen in other conditions

Question 11

Describe palmoplantar psoriasis

Answer 11

• Very thick hyperkeratotic skin on soles of feet and palms of hand
• Very encased - patients can peel off sheets of skin
• Sometimes confused with atopic dermatitis which can have similar appearances of hyperkeratosis - but look for scaly plaques elsewhere or nail changes indicative of psoriasis
• Very uncomfortable to walk or use hands - get deep fissures in skin where it has cracked

Question 12

What are the two peak age groups of onset of psoriasis?

Answer 12

2nd/3rd decade and 6th decade

Question 13

What are the precipitating factors for psoriasis (on top of genetics/family history)?

Answer 13

1) Streptococcal pharyngitis or other infection
2) Emotional stress
3) Physical trauma
4) Drugs - lithium, beta blockers, NSAIDs, antimalarials
5) HIV infection

Question 14

What happens in psoriasis?

Answer 14

1) Skin specific effects trigger psoriasis
2) This stimulates innate and adaptive immunity which causes propagation of psoriasis
3) This leads to increased cell turnover and vasodilation causing excess skin with silvery scale

Question 15

What are some of the inflammatory pathways involved in psoriasis?

Answer 15

1) Impaired barrier function

2) APCs cause propagation of inflammatory pathways e.g. IL-17, IL-23, TNFalpha (and IL-22?) which drive psoriasis

Question 16

What are comorbidites of psoriasis?

Answer 16

1) Depression
2) Diabetes
3) Psoriatic arthritis
4) Heart disease (but other risk factors also present)
5) Obesity
6) Metabolic syndrome

Question 17

What lifestyle change can lead to an improvement in psoriasis?

Answer 17

Weight reduction

Question 18

What indexes are used to measure the effect of psoriasis on mental health?

Answer 18

1) Dermatology life quality index (DLQI 1-30)
2) Patient health questionnaire (PHQ9)
3) Generalised anxiety disorder (GAD7)

Question 19

What does severe psoriasis increase your risk of?

Answer 19

• Stroke and MI

- Depression, anxiety, suicidality

Question 20

Where is the majority of psoriasis treated?

Answer 20

In primary care

Question 21

How is psoriasis treated topically?

Answer 21

1) Thick moisturisers (2-3 times a day in flare)
2) Corticosteroid ointments
3) Vitamin D analogues (combination or monotherapy)
4) Tar/retinoids on skin e.g. dithranol - good for stubborn thick plaques on skin

Question 22

What is the problem with topical steroids?

Answer 22

• Can get rebound
• After using a strong, potent topical steroid when you suddenly stop using it psoriasis can come back worse
• So tend to use slightly weaker topical steroids and then gradually wean them off

Question 23

How is phototherapy used to treat psoriasis?

Answer 23

• UV has an immunosuppressive effect on the skin
• Will give them 6 months relief
• May be a good maintenance treatment and all they need
• Contraindications = previous skin cancer or v fair skin which is likely to burn

Question 24

What medications are prescribed as 2nd line systemics (prescribed by dermatologists) in psoriasis?

Answer 24

1) Methotrexate
2) Acitretin - good for thickened skin, helps reduce hyperkeratosis
3) Cyclosporin - v effective, can’t use long term (> year) bc can cause damage to kidney and high BP so often rescue therapy
4) Fumaric acid esters
5) Apremilast - used in patients not suitable for a biologic

Question 25

When would you offer a biologic to a psoriasis patient?

Answer 25

1) If MTX and cyclosporin have failed, are not tolerated or are contraindicated
2) The psoriasis has a large impact on physical, psychological or social function (DLQI > 10)
3) Psoriasis is extensive (BSA > 10%) or PASI ≥ 10
4) Psoriasis is severe at localised sites (difficult to treat areas or nail disease) and associated with significant functional impairment and/or high levels of distress

Question 26

What is the PASI score used for in psoriasis?

Answer 26

Used to assess severity of psoriasis based on erythema, scaling and thickness of plaques

Question 27

Which biologics are used in psoriasis?

Answer 27

1) Anti-IL-17 - Secukinumab
2) Anti-IL-23/12 - Ustekinumab
3) Anti-TNFalpha - infliximab, adalimumab, etanercept

Question 28

Are biologics effective in psoriasis?

Answer 28

V effective, but may have to switch therapies if not good response or lose good response or have side effects

Question 29

What has been the effect of biologics?

Answer 29

90% reduction in inpatient admissions with patients with erythrodermic psoriasis

Question 30

What is erythroderma?

Answer 30

Red rash with 90% BSA involvement

Question 31

What are the features of erythroderma?

Answer 31

• Scaly red inflamed skin
• 90% body surface area involvement
• Skin is so inflamed that can’t thermoregulate well so lose lots of fluid through the skin
• Patient is often unwell due to problems with thermoregulation, fluid balance, hypovolaemia and hypoalbuminaemia

Question 32

How do you treat patients with erythroderma?

Answer 32

1) Inpatient admission
2) Bed rest
3) Cover them in topical emollients to try and replicate their skin barrier and its normal function - can be v effective
4) Systemic/biologic therapy if topical doesn’t work

Question 33

How do you diagnose erythroderma?

Answer 33

History, clinical signs, skin biopsy

Question 34

What are causes of erythroderma?

Answer 34

1) Drug eruption
2) Dermatitis e.g. atopic,. seborrhoeic, contact
3) Psoriasis
4) Pityriasis rubra pilaris
5) Infection - staphylococcal scalded skin syndrome
6) Blistering disease - pemphigus and pemphigoid
7) Sezary syndrome (cutaneous T cell lymphoma)