2 - psoriasis Flashcards
what is psoriasis?
common chronic inflammatory condition triggered by environmental factors in genetically susceptible people
what are some triggering factors for psoriasis?
- stress
- trauma
- alcohol & smoking
- infection (strep throat)
- drugs (beta blockers, lithium, antimalarials, swift withdrawal, steroids)
what is pathophysiology of psoriasis?
- keratinocytes under stress (from triggers) & release factors stimulating inflammatory cells
- cascade is made involving dendritic cells and activating T cells etc
- neutrophils at keratin layer = called munro micro abscesses
- keratinocyte proliferation & dermal fibroblasts involved
what is clinical presentation of psoriasis?
- symmetrical red, scaly patches w well defined edges
- common at scalp, elbows, knees
- silvery white scale
- itchy
what is issue with steroids in psoriasis?
cautious w steroids because while treated w steroids keeps under control but as soon as stop steroids then big flare up
what is koebner phenomenon?
when psoriasis develops in area of trauma (sunburn, scratches, contact dermatitis, surgical trauma)
what is auspitz sign?
bleeding point where surface scale removed in psoriasis
what are nail changes seen in psoriasis?
- nail bed pitting
- onycholysis
- subungual hyperkeratosis (thickening)
what is chronic plaque psoriasis?
most common type psoriasis = symmetrical plaques on extensor surfaces
what is flexural/inverse psoriasis?
type where smooth, erythematous plaques on flexor surfaces. colonised by candida yeast
what is guttate psoriasis?
multiple small, tear drop shaped, erythematous plaques on trunk after strep infection in YA
what is pustular psoriasis?
multiple petechiae & pustules on palms & soles
what is generalised/erythrodermic psoriasis?
rare but serious form characterised by erythroderma & systemic illness
what investigations done for psoriasis?
= rarely done (mostly clinical) but can do biopsy showing (thickened epidermis w keratin, parakeratosis, neutrophil accumulation, elongated rete pegs)
what is management of psoriasis?
= emollient (for scale & itch)
1st line - topical corticosteroid + vitD
- also coal tar, dithranol, keratolytics (salicylic acid), retinoids (lazarotene)
