Psoriasis medication

Using topical steroids in psoriasis

as we know topical corticosteroid therapy may lead to skin atrophy, striae and rebound symptoms
- the scalp, face and flexures are particularly prone to steroid atrophy so topical steroids should not be used for more than 1-2 weeks/month
systemic side-effects may be seen when potent corticosteroids are used on large areas e.g. > 10% of the body surface area
NICE recommend that we aim for a 4-week break before starting another course of topical corticosteroids
they also recommend using potent corticosteroids for no longer than 8 weeks at a time and very potent corticosteroids for no longer than 4 weeks at a time

Vitamin D analogues

examples of vitamin D analogues include calcipotriol (Dovonex), calcitriol and tacalcitol
they work by ↓ cell division and differentiation → ↓ epidermal proliferation
adverse effects are uncommon
unlike corticosteroids they may be used long-term
unlike coal tar and dithranol they do not smell or stain
they tend to reduce the scale and thickness of plaques but not the erythema
they should be avoided in pregnancy
the maximum weekly amount for adults is 100g

Dithranol