Psoriasis Flashcards
what is psorasis?
chronic autoimmune disease characterised by well-dermarcated, erythematous, scaly plaques
what are the 5 types of psoriasis?
- chronic plaque
- flexural (inverse)
- guttate
- pustular
- generalised/erythodermic
what is chronic plaque psoriasis?
- commonest type
- symmetrical plaques on the extensor surfaces, scalp and lower back
what is flexural (inverse) psoriasis?
- smooth, erythematous plaques without scale
- in flexures and skin folds
what is guttate psoriasis?
- multiple small, tear-drop shaped erythematous plaques
- occur on the trunk
- after a streptococcal infection in young adults
what is pustular psoriasis?
- multiple petechiae and pustules
- on palms and soles
what is generalised/erythrodermic psoriasis?
- rare but serious
- erythroderma and systemic illness
describe the typical cutaneous manifestation of psoriasis
itchy, well-dermarcated circular-to-oval bright red/pink elevated lesions (plaques) with overlying white or silvery scale, distributed symmetrically over extensor body surfaces and scalp
what nail changes are seen in psoriasis?
- nailbed pitting
- onycholysis (separation of nail plate from nailbed)
- subungual hyperkeratosis (thickening of the nailbed)
what are the risk factors for triggering psoriasis?
- skin trauma (koebner phenomenon)
- infection - strep, HIV
- drugs
- withdrawal of steroids
- stress
- alcohol + smoking
- cold/dry weather
what drugs can trigger psoriasis?
- lithium
- beta-blockers
- NSAIDs
- ACEi
- TNF-alpha inhibitors
- anti-malarials (e.g. chloroquine and hydroxychloroquine)
what are the risk factors for developing psoriasis?
- family history
- HIV infection
- obesity
- smoking
what is koebner phenomenon?
skin lesions occur at sites of skin injury in otherwise healthy skin
what is the differential diagnosis for koebner phenomenon?
- psoriasis
- lichen planus
- vitiligo
how does vitamin D help psoriasis?
reduces keratinocyte proliferation
what is the topical treatment of psoriasis?
- potent topical corticosteroid OD (e.g. betnovate) + topical vitamin D OD (e.g. dovonex)
- stop corticosteriod + topical vitamin D BD
- stop vitamin D + potent corticosteroid BD
dithranol + tar = alternatives
what is the phototherapy management of psoriasis?
- narrowband UVB phototherapy
- psoralen + UVA (PUVA)
what is the systemic treatment of psoriasis?
- methotrexate
- ciclosporin (1st line if rapid disease control needed/palmoplantar pustulosis/contraception)
- acitretin
what biological treatment can be used in psoriasis?
- infliximab
- etanercept
- adalimumab
what is the strength of different topical steroids?
“Help Every Budding Dermatologist”
mild = Hydrocortisone 0.5%
moderate = Eumovate
potent = Betnovate
very potent = Dermovate
potent/very potent NOT for face or genitals
very potent only to be prescribed by dermatologists
what are the side-effects of acitretin?
- teratogenic
- hepatotoxicity
- elevated lipids
what are the side-effects of ciclosporin?
5 H’s:
Hypertrophy of the gums
Hypertrichosis
Hypertension
Hyperkalaemia
Hyperglycaemia
