8.5 - Psoriasis & Drugs For Psoriasis

Front 1

Psoriasis
- epidemiology
- triggers?

Back 1

- bimodal: 16-22, 57-60
- injury, sunburn, strep, alcohol, stress, and drugs: ACEIs, lithium, terbinafind, indomethacin, interferon-a, chloroquine, NSAIDs, BB, quinolines

Front 2

What are some types of psoriasis?

Back 2

1. Stable plaque psoriasis, on extensors
2. Inverse psoriasis, on flexures
3. nail psoriasis (pitting, fraying, discloration) affects 50-80% other types
4. guttate psoriasis - abrupt onset plaque on trunk of children or young adults after strep pharyngitis. usually clears forever.
5. diffuse redness without or with less plaques, typically due to overuse of steroids or light therapy
6. generalised pustular psoriasis - widespread redness and sterile pustules - can be fatal due to heart failure
7. pustular psoriasis on hands and feet, which can be painful, without plaques

5-30% also have psoriatic arthritis

Front 3

Initial treatment of stable plque psoriasis?

Back 3

1. moisturise - softens scales
2. keratolytics - salicylic acid - increases penetration of topical agents
3. Coal tar - slower acting but may retain remission longer; good for scalp and widespread disease
5. Dithranol - effective at high conc for short periods, or lower conc e.g. overnight
6. Steriods - faster than coal tar and dithranol. Can be used in face, flexures, genitals (unlike coal tar and dithranol). Faster relapse. Tacchyphylaxis.

Front 4

Next treatment of psoriasis?

Back 4

1. calcipotriol & topical tazarotene - similar efficacy to coal tar and steroids without tolerance; long term use not studied; irritant
2. Phototherapy with UVB preferred over photochemotherapy with UVA and methoxsalen; risk of skin cancer
3. Acitretin - 10-20% discontinue because of A/Es, good for pustular and erythrodermic psoriasis but not as good for plaque psoriasis.
4. MTX and cyclosporin are more common and effective than hydroxyurea
5. Immunomodulators as for RA: etanercept, alefacept, infliximab (LAST LINE)

Front 5

What about additional therapy, combos and rotational therapies?

Back 5

1. may need ABX
2. Coal tar and dithranol with UVB, acitretin with UVB, MTX with UVB, MTX with cyclospotin
3. Acitretin, MTX, UVB +/- coal tar and dithranol, cyclosporin

Front 6

What about just plain scalp psoriasis?

Back 6

coal tar
dithranol
salicylic acid
calciportiol
corticosteroids

Front 7

Calcipotriol
- product
- MOA
- CI
- Caution

Back 7

Davionex (0.005% calcipotriol)
Daivobet 50/500 (0.05% B.D., 0.005% calcipotriol)

Vitamin D analogues, suppresses proliferation and keritonycytes

CI: calcium metabolism disorders; avoid use in severe disease because of risk of hypercalcaemia

Front 8

Daivonex
- A/E
- dose
- counselling

Back 8

Mild burning or stinging

Apply aa bd. (Reduce to d application if possible, stop when satisfactory control achieved). Maximum of 100g cream or 60mL liquid weekly.

For Daivobet, apply daily, max 100g weekly, max 30% body surface.
How to use:
- may need to use for 4-6/52
- avoid face and flexurs: redness
- wash hands
Interactions:
- do not mix with other preparations because may destroy calcipotrilol (salicylic acid, UVA)
- do not take Ca, Vit D - monitor ca and RF every 3/12 if >100g weekly.

S/Es
- L8

Front 9

Salicylic acid
- CI
- Cautions
- Preg/BF
- A/Es

Back 9

CI: moles, face, inflamed skin
Caution: diabetes, children (smaller SA:V ratio: higher absorption)
Preg: data lacking, only on small areas
BF: safe on small areas

NO common S/Es
Infrequent irritation
Rare: salicylic intoxication: tinnitus, confusion, dizziness, death

Front 10

Salicylic Acid
- use with occlussion ok?
- normal concentration for psoriasis?
- beneficial DI?
- dose?

Back 10

- ok to remove scales overnight e.g. with a shower cap
- 2-6%
- potentiates dithranol, coal tar, steroids
- Start with d application. Increase to bd-tds (to avoid drying)