Psoriasis Flashcards
What is psoriasis?
- autoimmune disease
- inflammatory skin condition
- chronic
- causes hyperproliferation of keratinocytes
Types of psoriasis
- chronic plaque psoriasis
- guttate
- seborrhoeic
- flexural (inverse)
- pustular
- palmoplantar pustulosis
- erythrodermic
What is auspitz sign?
scratch and gentle removal of psoriatic scales causes capillary bleeding
How does plaque psoriasis present?
- well-demarcated, red, raised plaques
- covered by flakey silvery-white scales
- itchy
- typically on extensor surfaces, may be on scalp
- nail changes in 50%
- psoriatic arthritis in some
What are raindrop lesions characteristic of?
guttate psoriasis
How does guttate psoriasis present?
- raindrop lesions (small, red, individual papules) on trunk, limbs, sometimes scalp (not palms or soles)
- often preceding infection e.g. strep throat
- often presents in childhood
How does flexural/inverse psoriasis present?
- in flexures (skin folds)
- smooth, shiny red lesions
- more common in overweight people
How does pustular psoriasis (von Zumbusch psoriasis) present?
- erythema, initially on flexor surfaces before spreading to other body surfaces
- tender skin
- small, sterile pustules
- pustules dry and peel within 2 days leaving skin glazed and smooth
- may have systemic Sx: fever, chills, severe itching, tachycardia, exhaustion
- may be induced by suddenly stopping steroids
- can be life-threatening
How does palmoplantar pustolosis present?
- a form of pustular psoriasis
- sterile pustules and yellow-brown macules on palms and soles (that then peel off)
- can progress to deep fissures
- can be life-threatening
How does erythrodermic psoriasis present?
- generalised erythema affecting >90% of the body
- facial sparing
- nail changes
- itching and pain
- scales fall off in sheets
- severe, unstable, highly labile disease
- affects ability to control temperature
- may need admission
- dermatological emergency, can be life-threatening
How does photosensitive psoriasis present?
- in association with sunburn
- guttate lesions or painful diffuse inflamed plaques in areas of sunburn
How does HIV-induced psoriasis present?
- may be atypical, unusually severe
- may have sudden onset of Sx including pustular or erythroderma
What nail changes may be seen in psoriasis
- pitting
- onycholysis (separation from nail bed)
- subungal hyperkeratosis (keratin build-up in space created by onycholysis)
- salmon patches/oil-spots (reddish discolouration)
Presentations of psoriatic arthritis
DR SAM DIP joint involvement Rheumatoid-like Spondyloarthritis Asymmetrical oligoarthritis Mutilans arthritis
Pharmacologiacal Mx of psoriasis
- emollients
- vitamin D analogue (calciprotriol) + potent topical corticosteroid (e.g. betamethasone valerate 0.025%) applied once a day but at different time to eachother
- if scales are problematic: topical salicyclic acid 2-3x/week
Also:
- topical retinoids
- scalp preparations
- dithranol (athralin)
- coal tar preparations
- topical calcineurin inhibitors
