Psoriasis

Question 1

What is it and what does it increase the risk o f

Answer 1

red, scaly patches on the skin although it is now recognised that patients with psoriasis are at increased risk of arthritis and cardiovascular disease.

Question 2

Genetic association

Answer 2

HLA-B13, -B17, and -Cw6. Strong concordance (70%) in identical twins

Question 3

Immunological pathophysiology

Answer 3

abnormal T cell activity stimulates keratinocyte proliferation. There is increasing evidence this may be mediated by a novel group of T helper cells producing IL-17, designated Th17. These cells seem to be a third T-effector cell subset in addition to Th1 and Th2

Question 4

What are the environmental triggers

Answer 4

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

Question 5

wHAT EXACERBATES PSORIASIS

Answer 5

trauma
alcohol
drugs: beta blockers, lithium, antimalarials (chloroquine and hydroxychloroquine), NSAIDs and ACE inhibitors, infliximab
withdrawal of systemic steroids

Question 6

What are the subtypes

Answer 6

Plaque, flexural, guttate, pustular

Question 7

What is plaque psoriasis

Answer 7

the most common sub-type resulting in the typical well-demarcated red, scaly patches affecting the extensor surfaces, sacrum and scalp

Question 8

What is flexural psoriasis

Answer 8

in contrast to plaque psoriasis the skin is smooth

Question 9

What is guttate psoriasis

Answer 9

transient psoriatic rash frequently triggered by a streptococcal infection. Multiple red, teardrop lesions appear on the body

Question 10

What is pustular psoriasis

Answer 10

commonly occurs on the palms and soles

Question 11

How does it effect nails

Answer 11

Affects both finger and toe nails (80% of those with psoriatic arthropathy have it)

Question 12

What nail changes will be seen

Answer 12

pitting
onycholysis (separation of the nail from the nail bed)
subungual hyperkeratosis
loss of the nail

Question 13

What are the other features of psoriasis

Answer 13

nail signs: pitting, onycholysis
arthritis

Question 14

Complications

Answer 14

psoriatic arthropathy (around 10%)
increased incidence of metabolic syndrome
increased incidence of cardiovascular disease
increased incidence of venous thromboembolism
psychological distress

Question 15

What is seen in chronic plaque psoriasis

Answer 15

erythematous plaques covered with a silvery-white scale

Question 16

Where is plaque psoriasis located

Answer 16

extensor surfaces such as the elbows and knees. Also common on the scalp, trunk, buttocks and periumbilical area - clear delineation between normal and affected

Question 17

How big are the plaques

Answer 17

1-10cm

Question 18

What happens when the plaques are removed

Answer 18

Auspitz sign

Question 19

Who gets guttate psoriasis

Answer 19

Kids and teens

Question 20

What is guttate precipitated by

Answer 20

streptococcal infection 2-4 weeks prior to the lesions appearing.

Question 21

What are the features of guttate

Answer 21

tear drop papules on the trunk and limbs
gutta is Latin for drop
pink, scaly patches or plques of psoriasis
tends to be acute onset over days

Question 22

How to manage guttate

Answer 22

most cases resolve spontaneously within 2-3 months
there is no firm evidence to support the use of antibiotics to eradicate streptococcal infection
topical agents as per psoriasis
UVB phototherapy
tonsillectomy may be necessary with recurrent episodes

Question 23

Management of chronic plaquers

Answer 23

regular emollients may help to reduce scale loss and reduce pruritus
first-line: NICE recommend:
a potent corticosteroid applied once daily plus vitamin D analogue applied once daily
should be applied separately, one in the morning and the other in the evening)
for up to 4 weeks as initial treatment

Question 24

What is second line

Answer 24

if no improvement after 8 weeks then offer a vitamin d analogue

Question 25

What is third line

Answer 25

f no improvement after 8-12 weeks then offer either:
a potent corticosteroid applied twice daily for up to 4 weeks, or
a coal tar preparation applied once or twice daily
short-acting dithranol can also be used

Question 26

What secondary management may be used

Answer 26

Phototherapy and systemic therapy

Question 27

What is involved in phototherapy

Answer 27

narrowband ultraviolet B light is now the treatment of choice. If possible this should be given 3 times a week
photochemotherapy is also used - psoralen + ultraviolet A light (PUVA)
adverse effects: skin ageing, squamous cell cancer (not melanoma)

Question 28

What is involved in systemic therapy

Answer 28

oral methotrexate is used first-line. It is particularly useful if there is associated joint disease
ciclosporin
systemic retinoids
biological agents: infliximab, etanercept and adalimumab
ustekinumab (IL-12 and IL-23 blocker) is showing promise in early trials

Question 29

What to do for scalp psoriasis

Answer 29

NICE recommend the use of potent topical corticosteroids used once daily for 4 weeks
if no improvement after 4 weeks then either use a different formulation of the potent corticosteroid (for example, a shampoo or mousse) and/or a topical agents to remove adherent scale (for example, agents containing salicylic acid, emollients and oils) before application of the potent corticosteroid

Question 30

What to do for Face, flexural and genital psoriasis

Answer 30

NICE recommend offering a mild or moderate potency corticosteroid applied once or twice daily for a maximum of 2 weeks

Question 31

How long to use topical steroids on scalp face and flexures

Answer 31

should not be used for more than 1-2 weeks/month - skin atrophy

Question 32

When are systemic side effects seen

Answer 32

> 10% body use

Question 33

How long in between using another corticosteroid

Answer 33

4 week break

Question 34

How long can you use potent corticosteroids

Answer 34

8 weeks at a time

Question 35

How long can you use very potent

Answer 35

No more than 4 weeks

Question 36

Examples of Vit D analogues

Answer 36

calcipotriol (Dovonex), calcitriol and tacalcitol

Question 37

How do the Vin D analogues work

Answer 37

they work by ↓ cell division and differentiation → ↓ epidermal proliferation

Question 38

What are the benefits of Vitamin D use

Answer 38

adverse effects are uncommon
unlike corticosteroids they may be used long-term
unlike coal tar and dithranol they do not smell or stain

Question 39

What do they do to plaques

Answer 39

they tend to reduce the scale and thickness of plaques but not the erythema

Question 40

Maximum dose and when should be avoided

Answer 40

they should be avoided in pregnancy
the maximum weekly amount for adults is 100g

Question 41

How does dithranol work

Answer 41

inhibits DNA synthesis
wash off after 30 mins
adverse effects include burning, staining

Question 42

How to treat flexor psoriasis

Answer 42

Remember that the treatment of flexural psoriasis differs from extensor psoriasis. The skin of flexure areas of the body is much thinner and more sensitive to steroids compared to the extensor surfaces. Flexural surfaces that tend to be affected are the groin, genital region, axillae, inframammary folds, abdominal folds, sacral and gluteal cleft.

In this case, the patient’s axillae are affected and treatment should begin with a mild- or moderately-potent corticosteroid (applied once or twice daily) for up to two weeks, as per NICE guidelines.

Vit D not found to be beneficial for this case

Question 43

You are reviewing a 46-year-old man with a known diagnosis of chronic plaque psoriasis affecting his elbows and knees. He was seen by one of your colleagues 8 weeks ago and was given a combination of vitamin D and a potent corticosteroid for a flare of symptoms. He has been using this daily. Prior to this, he was only using emollients.

There has been some improvement, but you both agree that he needs further treatment to control this flare. Which of the above would be the next most appropriate step in management?

Answer 43

A topical vitamin D preparation alone

This patient has had 8 weeks of a potent steroid. According to NICE this should be stopped now and the next line in treatment should be applying a vitamin D analogue twice daily. You would review him again after 8-12 weeks.

According to NICE guidance, he should have been started on a potent steroid and a separate vitamin D preparation. Combined preparations are recommended much later in the treatment algorithm. In practice however, you will find that not everyone will follow guidelines strictly. In this case, it is important to remember to limit potent steroid applications to 8 weeks followed by at least a 4-week break.