Psoriasis

Question 1

Define psoriasis

Answer 1

Chronic skin disorder
Red, scaly patches on extensor surfaces
Keratinocytes disorder

Question 2

What is the pathology of psoriasis?

Answer 2

Keratinocytes -> proliferate and secrete more keratin -> uncontrolled keratin plaques -> epidermal hyperplasia
Can be triggered by immune and environmental factors.

Question 3

What genes are associated with psoriasis?

Answer 3

HLA-B13 B16 and Cw6

Question 4

What are some drugs associated with worsening psoriasis?

Answer 4

Beta blockers
Lithium

Question 5

What environmental factors can worsen psoriasis?

Answer 5

Trauma - Koebner phenomenon
Infection - HIV and strep
Stress
SMoking
Alcohol
Obesity
Lack of sunlight

Question 6

What is the most common type of psoriasis?

Answer 6

Plaque psoriasis

Question 7

What are the key features of plaque psoriasis?

Answer 7

Well defined red scaly plaques with silver discolouration
Pin point bleeding (auspitz sign)
Extensor surface and scalp
Itching -> can cause lichenification
Pigment changes as placks clear

Question 8

What are the different types of psoriasis?

Answer 8

1. Plaque
2. Flexoral -> skin folds, less scale more shint
3. Guttate
4. Pustular -> yellow/brown below skin, hands and feet
5. Erythrodermic

Question 9

What type of psoriasis is this?
Features

Answer 9

Guttate psoriasis = follows strep infection, widespread water drop lesions, trunk

Question 10

What types of psoriasis are a medical emergency?

Answer 10

Erythrodermic
Pustular

Question 11

What are the features of nail psoriasis?

Answer 11

Discolouration
Pitting
Onychloysis
Subungal hyperkaratosis
Loss of the nail

Question 12

What are the potential complications of psoriasis?

Answer 12

Psoriatic arthropathy
Metabolic syndrome
Cardiovascular disease
VTE
Psychological distress

Question 13

What drugs can exacerbate psoriasis?

Answer 13

beta blockers
Lithium
Anti-malarials - chloroquine and hydroxychloroquine
NSAIDs
Aceinhibitors
Infliximab
Withdrawl of systemic steroids

Question 14

What is the recommended management for chronic plaque psoriasis?

Answer 14

Regular emmolients
NICE - first line topical corticosteroid plus Vitamin D analogue (not at the same time)
If no improvement after 8w - Vitamin D twice daily

Question 15

What secondary care management may be offered for psoriasis?

Answer 15

Phototherapy
Oral methotrexate, ciclopsorin, retinoids, biologics,

Question 16

How should scalp psoriasis be treated?

Answer 16

Potent topical corticosteroid once daily for 4w

Question 17

What is importance safety advice about the use of steroids for psoriasis?

Answer 17

Risk of skin atrophy, striae and rebound symptoms
Not use more than 1-2w per month
Systemic side effects if >10% body area
4 week break before strating again

Question 18

What is important about the use of Vitamin D analogues to treat psoriasis?

Answer 18

Decrease cell division and epidermal proliferation
Can be used long term
Avoid in pregnancy
Reduce scale but not erythema

Question 19

What are the risks of dithranol used to treat psoriasis?

Answer 19

Inhibits DNA synthesis - must be washed off after 30mins, risk of burning and staining (brown/red)