Psoriasis

Question 1

Pathophysiology of psoriasis

Answer 1

Increase proliferation and decrease differentiation of keratinocytes caused by autoimmune inflammation (see flow chart)

Question 2

Psoriasis treatment: Topical

Answer 2

1. Emollients/ Keratolytics
2. Tars/ Dithranol
3. Corticosteriods
4. Vitamin D analogue
5. Retinoids

Question 3

Psoriasis treatment: Systemic

Answer 3

1. Antibiotics
2. Methotrexate
3. Cyclosporin
4. Retinoids
5. Phototherapy

Systemic therapies should be rotated to avoid serious adverse effects from prolonged exposure

Question 4

Signs of Psoriasis

Answer 4

Well defined raised plaque with silvery scale
Erythema
No vesicles

Question 5

Symptoms of Psoriasis

Answer 5

May be asymptomatic

- Some degree of itch (acute inflammatory form or in scalp, flexures and perianal area)

Question 6

Where is Psoriasis most commonly seen

Answer 6

Elbows and Knees
Flexures
Drier areas (trunk, scalp, palms)
Nails

Question 7

What are some general advice for patients with Psoriasis

Answer 7

Stress management
Exercise
Stop smoking
Reduce alcohol intake
Avoid precipitating factors i.e.. Drugs
Weight reduction
Support networks

Question 8

What are some barriers in using Tar and how would you overcome these?

Answer 8

Tars can smell, stingy, stain clothing and be time consuming to apply.
Inform the patient that tars are very beneficially in reducing inflammation and itch, and give advice on how to use it: Apply at night before bed, wear old clothes and use old bed linen

Question 9

What is a disadvantage of using Corticosteriods?

Answer 9

Tachyphylaxis

Question 10

Calcipotriol: How it works and S/E

Answer 10

Regulated keratinocyte proliferation and differentiation
Takes up to 6 weeks for peak effect
Overuse may cause hypercalcaemia
May cause erthyma and irritation (face and flexures)
Photosensitivity

Question 11

Methotrexate

Answer 11

Slows epidermal cell proliferation by inviting folic acid production
Dose: 1 weekly
Monitor FBC, renal, liver function
ADR: GI S/E, elevation of liver enzymes (Folic acid)
Drug interactions!

Question 12

What are some counselling points for cyclosporin?

Answer 12

Need to visit the dentist regularly: Gingival hyperplasia
Blood tests: Neoplasia, Renal function
Can increase photosensitivity- increase risk of skin cancer
Drug interactions
Excess hair growth (Hirsutism)

Question 13

What is phototherapy?

Answer 13

Carefully controlled exposure to UV radiation

More efficacious when used with acitretin (systemic retinoid)