Psoriasis Flashcards

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1
Q

What is Psoriasis ?

A
  • It is a chronic inflammatory skin condition characterised by clearly defined, red and scaly plaques (thickened skin).
  • It has a chronic, relapsing and remitting course
  • It is classified into several subtypes
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2
Q

Who most commonly gets Psoriasis ?

A
  • Can affect any age group but prevelence peaks in the 2nd and 5th decades of life
  • Caucasians most commonly get it
  • 1/3rd of patients with psoriasis have family members with psoriasis
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3
Q

What is the cause of psoriasis ?

A

The cause of psoriasis is multifactorial and not yet fully understood factors contributing include:

  1. Genetics: psoriasis prevelence is higher in people with these human leucocyte antigens - HLA-B13, -B17, & -Cw6.
  2. Immunological: abnormal T cell activity stimulates hyperproliferation of epidermal cells (e.g. keratinocytes). This may be mediated by T helper cells (Th17) producing IL-17. This results in increased number of cells entering cell cycle from the basal layer and a faster epidermal turnover time.
  3. Environmental: it is recognised that psoriasis may be worsened (e.g. Skin trauma, stress), triggered (e.g. Streptococcal infection) or improved (e.g. Sunlight) by environmental factors
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4
Q

What are the histological features of psoriasis ?

A
  • Hyperkeratosis
  • Parakeratotic stratum corneum (contains nuclei – normally none)
  • Absence of granular layer
  • Expanded prickle cell layer
  • Rete ridge elongation
  • Large capillary vessels in papillary dermis
  • Leucocytes – Munro microabscesses in stratum corneum
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5
Q

List some of the precipitating environmental factors for psoriasis ?

A
  • Emotional Stress
  • Infection – strep throat and guttate psoriasis
  • Drugs – Beta-blockers, lithium, anti-malarials, withdrawal of topical or systemic steroids
  • Alcohol
  • Trauma – Koebner phenomenon
  • Smoking
  • HIV / AIDS
  • ( Ultraviolet irradiation – in 10% it worsens)
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6
Q

What is Koebner phenomenom ?

A

This is where psoriasis develops in sites of trauma 2-6weeks after the trauma is sustained. Examples of trauma it may devleop in include:

  • Scratches
  • Burns ( & sunburn)
  • Other dermatoses e.g. contact dermatitis
  • Surgical trauma
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7
Q

What is the typical distribution of psoriasis ?

A

The most common sites are scalp, elbows and knees, but any part of the skin can be involved.

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8
Q

What are the clinical features of psoriasis ?

A
  • Usually symmetrically distributed red, scaly plaques with well-defined edges.
  • The scale is typically silvery white, except in skin folds where the plaques often appear shiny and they may have a moist peeling surface.
  • Itch is usually mild but can be severe leading to scratching and lichenification.
  • Painful skin cracks or fissures may occur.
  • When psoriatic plaques clear up, they may leave brown or pale marks that can be expected to fade over several months.
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9
Q

List the main sub-types of psoriasis

A
  • Guttate psoriasis
  • Chronic plaque psoriasis
  • Scalp psoriasis
  • Flexural psoriasis
  • Palmoplantar psoriasis
  • Nail psoriasis
  • Psoriatic arthritis
  • Generalised pustulosis
  • Localised palmoplantar pustulosis
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10
Q

Describe the appearance of chronic plaque psoriasis

A
  • It presents as small to large, well-demarcated, erythematous scaly and thickened plaques.
  • Plaques are palpable, raised with silvery scale
  • Auspitz’ sign seen = removing scale reveals pin-point bleeding
  • May develop due to Koebner phenomenon
  • It most likely to affect extensor aspects of knees, elbows & sacrum
  • It is often accompanied by scalp and nail psoriasis
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11
Q

What are the typical clinical features of guttate psoriasis ?

A
  • Characterised by multiple small scaly plaques on the trunk and limbs. Looks like a shower of red, scaly teardrops that have fallen down on the body.
  • Usually occurs following a streptococcal infection of the throat or an upper respiratory tract viral infection.
  • Typically affects children & young adults (15-25)
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12
Q

What are the clinical features of scalp psoriasis ?

A
  • Characterised by red scaly thickened patches (plaques). It often affects the scalp, may extend slightly beyond hairline.
  • Scale is often silvery white
  • Can cause severe dandruff due to falking of the skin
  • May be very itchy
  • The back of the head is a common site for psoriasis, but multiple discrete areas of the scalp or the whole scalp may be affected.
  • May occur in isolation or with any other form of psoriasis.
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13
Q

What are the clinical features of flexural psoriasis ?

A
  • Affects skin folds & genitals
  • Due to the moist nature of the skin folds it presents differently. It tends not to have silvery scale, but is shiny and smooth.
  • There may be a crack (fissure) in the depth of the skin crease.
  • The deep red colour and well-defined borders characteristic of psoriasis may still be obvious.
  • Scaly plaques may sometimes occur
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14
Q

What are the clinical features palmoplantar psoriasis ?

A
  • Well-circumscribed, red, scaly, plaques similar to psoriasis elsewhere
  • Can be painful / disabling
  • Often very thick hyperkeratosis
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15
Q

What are the clinical features of erythrodermic psoriasis ?

A
  • It is rare but occurs in the setting of known worsening or unstable psoriasis
  • Features are of red dry skin all over the body (> 90%)
  • Causes include – withdrawal of potent topical or systemic steroids, drug reactions, ultraviolet burns etc
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16
Q

What complications can develop as a result of erythrodermic psoriasis ?

A
  • Hypothermia
  • Cardiogenic shock
  • Dehydration
  • Anaemia
  • Hypoproteinaemia

It is very serious and can be a fatal condition

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17
Q

What are the clinical features of nail psoriasis ?

A

Nail psoriasis can affect any part of one or more nails. There are often scaly plaques on the dorsum of the hands and fingers due to associated plaque psoriasis.

Psoratic nail changes include:

  • Nail pitting
  • Onycholysis = separation of the nail plate from the underlying nail bed
  • Leukonychia = areas of white on the nail plate
  • “oil-drop” lesions = a translucent yellow-red discolouration in the nail bed
  • Sub-ungal hyperkeratosis = scaling under the nail
  • Nail deformity
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18
Q

What psoriatic nail changes are shown in this pic ?

A

Leukonychia & Nail pitting

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19
Q

What are the clinical features of psoriatic arthritis ?

A
  • Symptoms include joint pain, swelling and stiffness.
  • Psoriatic arthritis is a painful, inflammatory condition of the joints that can occur in up to 30 per cent of patients with psoriasis.
  • Large and small joints may be affected.
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20
Q

What are the 5 main patterns of psoriatic arthritis ?

A
  1. Asymmetric oligoarthritis (60-70%)
  2. Symmetrical polyarthritis (15%)
  3. Distal phalangeal joint disease (5%)
  4. Destructive arthritis (arthritis mutilans – 5%)
  5. Axial arthritis (5%) (spondylitis / sacroiliitis)

Oligoarthritis = affecting 2-4 joints

Polyarthritis = affecting ≥ 4 joints

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21
Q

What are the clinical features of generalised pustular psoriasis ?

A
  • Generalised pustular psoriasis is characterised by recurrent acute flares.
  • It presents with widespread sterile pustules on a background of red and tender skin
  • Associated symptoms of Painful skin, fever, malaise
  • May develop Hypoalbuminaemia, hypocalcaemia and leucocytosis, liver failure, acute renal tubular necrosis. Can be fatal.
  • Causes include – withdrawal of steroids, infection, pregnancy, hypocalcaemia
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22
Q

What is palmoplantar pustulosis ?

A
  • A chronic pustular condition affecting the palms and soles
  • It is related to psoriasis and patients who develop it may also have lesions of psoriasis elsewhere
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23
Q

What are the clinical features of palmoplantar pustulosis ?

A
  • Presents as crops of sterile yellow pustules occurring on one or both hands and feet.
  • They are associated with thickened, scaly, red skin that easily develops painful cracks (fissures).
  • Strong association with cigarette smoking & usually occurs in older people (>50)
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24
Q

How is psoriasis diagnosed ?

A

Clinically

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25
Q

What do patients with generalised pustular psoriasis or erythrodermic psoriasis require ?

A

Emergency referral to dermatology

26
Q

What adjuvant therapy is also useful in the treatment of psoriasis ?

A

Regular use of emollients - may help reduce scale & pruritus

27
Q

In general what is the stepwise management of psoriasis ?

A
  • 1st line = topical therapies
  • 2nd line = phototherapy
  • 3rd line = Immunosuppressants
28
Q

For patients with psoriasis who dont respond to topical therapy in primary care what should be done ?

A

They should be referred to secondary care (dermatology) for 2nd & 3rd line treatments

29
Q

Where should psoriatic arthritis be managed ?

A

Should be assessed by a rheumatologist & treated (see rheumatology notes for treatment)

30
Q

Topical therapy is 1st line in the managment of psoriasis unless what?

A

Unless it is unlikely to control psoriasis such as:

  • For extensive disease (>10% of body affected)
  • OR ≥ moderate on physicians global assessment
  • OR where topical therapy is ineffective e.g. in nail disease

Offer second- or third-line treatment options (phototherapy or systemic therapy) at the same time with topical therapy in these cirumstances

31
Q

What is the 1st line management of chronic plaque psoriasis/psoriasis affecting trunk/limbs in primary care?

A
  • 1st line for gaining control acutely = potent TCS or potent TCS + Calipotrol ointment (vit D analogue)
  • Long-term management 1st line = Vit D analogue
  • Long term 2nd line = Coal tar (solution or cream), tazarotene gel or dithranol
32
Q

What is the 1st line management of scalp psoriasis ?

A
  • 1st line = Short term intermittent use of potent TCS OR a potent TCS + a Vit D analogue
    • For patients with thick scaling of the scalp add overnight application of salicylic acid, tar preparations, or oil preparations (eg olive oil, coconut oil)
33
Q

What is the 1st line management of Face, flexutal and genital psoriasis?

A
  • 1st line = a mild or moderate potency TCS
  • 2nd line = Vit D analogues or tacrolimus ointment
34
Q

What is the treatment of nail psoriasis ?

A

Offer the general 1st (topical), 2nd (phototherapy) & 3rd (immunosuppressants) line management of psoriasis

35
Q

What is the treatment of guttate psoriasis ?

A
  • Topical agents as per psoriasis + UVB phototherapy
  • Tonsillectomy may be necessary with recurrent episodes

Note - most cases resolve spontaneously within 2-3 months

36
Q

What is the secondary (2nd & 3rd line) management of psoriasis?

A
  • 1st line = narrow beam UVB phototherapy
  • 2nd line = Immunosuppressants (1st line = methotrexate, 2nd line = ciclosporin, 3rd line = acitretin)
37
Q

What is the management of erythrodermic & generalised pustular psoriasis ?

A

Emergency referral to dermatology. Treatment includes:

  • Fluid balance
  • Bed rest
  • Monitor protein levels
  • Emollients
  • Systemic immunosuppressants
38
Q

What is the management of palmoplantar pustulosis ?

A
  • 1st line = Psoralen (PO or topical) + PUVA
  • 2nd line = Immunosuppressant - ciclosporin 1st line in this instance
39
Q

How long should very potent TCS be used ?

A

No longer than 4 weeks

40
Q

How long should potent TCS be used ?

A

No longer than 8 weeks

41
Q

How long a break should be given between treatments with potent or very potent corticosteroids.

A

4 weeks

42
Q

Give examples of Vit D analogues

A

Calcipotriol (Dovonex), calcitriol and tacalcitol

43
Q

What is the mechanism of action of Vit D analogues ?

A

Reduce epidermal proliferation and restores a normal horny layer

44
Q

What are the benefits of Vit D analogues ?

A
  • Clean & no odour
  • Very few side effects - may sometimes cause irritation
45
Q

Give examples of the emollients used in psoriasis and how they should be applied

A
  • 50/50 WSP/LP, diprobase® etc…
  • Should be massaged into plaques regularly
46
Q

Give examples of coal tars used in treatment of psoriasis and state their mechanism of action

A
  • “Clean tars” – Alphosyl® , Exorex® , Carbodome
  • Work by Reducing DNA synthesis and epidermal proliferation
47
Q

What are the potential problems with coal tars?

A
  • Brown and smelly and can stain.
  • May irritate / rarely contact allergy
  • Folliculitis
  • Photosensitivity
48
Q

What is the mechanism of action of dithranol ?

A

Anti-mitotic (inhibits DNA synthesis)

49
Q

What are the main problems with dithranol?

A
  • Burns normal skin
  • Stains clothing and bedding purple
50
Q

What should potetnial TCS never be used for in psoriasis and why?

A

Generalised psoriasis – risk of rebound flare-up (erythroderma, pustular psoriasis)

51
Q

What is the phototherapy used in the treatment of psoriasis ?

A

UVB

52
Q

What is the chemophototherapy which may be used in the treatment of psoriasis ?

A

PUVA = Psoralen (PO or topical) + UVA

53
Q

What are the potential acute & chronic side effects of phototherapy used in the treatment of psoriasis ?

A

Acute:

  • Erythema
  • Blistering
  • Photoconjunctivitis
  • Exacerbation of Herpes Simplex

Chronic:

  • Photoageing
  • Photocarcinogenesis
54
Q

What should be taken by someone on methotrexate and what monitoring is required ?

A
  • Folic acid taken concomittantly
  • Regular monitoring of FBC, U+E’s, LFT’s
  • PIIINP (non-invasive test for methotrexate induce liver fibrosis) every 4 months
55
Q

What monitoring is required for someone on ciclosporin ?

A

FBC, U+E’s, LFT’s, cholesterol and GFR

56
Q

What are the main potential side effect of ciclosporin?

A

Hypertension and renal impairment

57
Q

What monitoring is requried for someone on a retinoid ?

A

Monitor FBC, U+E’s, LFT’s, cholesterol and triglycerides

58
Q

Give an example of the main retinoid which may be used in the treatment of psoriasis ?

A

Acitretin

59
Q

Label the following nail signs and name the condition that all these nail signs are associated with ?

A
60
Q

List some of the complications associated with psoriasis

A
  • Psoriatic arthropathy (around 10%)
  • Increased incidence of metabolic syndrome, CVD & VTE
  • Psychological distress