Psoriasis Flashcards
Psoriasis
Non contagious, chronic, autoimmune skin inflammation that is very itchy and forms silver plaques
Psoriasis is associated with?
Psoriatic arthritis
Layers of skin?
Stratum basale
Stratum spinosum
Stratum granulosum
Stratum lucidum (only thick skin like palms and soles)
Stratum corneum
Pathogenesis of psoriasis
Microbe enters skin through a break in skin. Dendritic cell present it to T cells and it releases cytokines leading to chronic excessive inflammation and increased keratinocyte proliferation with recruiting WBCs. Maybe genetic or environmental
What is the effect of inflammation in psoriasis?
Inflammation > Blood vessel dilated in dermis > neutrophils come in the epidermis and collect in stratum corneum. Keratinocytes proliferate and mature abnormally. Thinning of basal layer occurs but thickened stratum corneum is formed and cells pile up.
Keratinocytes defects
More obvious in stratum corneum
Produce more keratin
Parakeratosis (retain nuclei)
Don’t adhere properly leading to breaks in the skin and therefore scaly appearance
Auspitz sign (bleeding as scales are picked off)
Kinds of psoriasis
Plaque psoriasis
Gluttate psoriasis
Inverse psoriasis
Pustulur psoriasis
Eryhthrodermic psoriasis
Psoriatic arthritis
Features of plaque psoriasis (4)
Flattened areas of elevation
Inflammed and red
White silver scales
Nail pitting
Features of guttate psoriasis (4)
Small red drop like spots
In childhood
Usually after infection
Nail pitting
Features of inverse psoriasis
Smooth and shiny red lesions
Nail pitting
Features of pustular psoriasis (4)
Red skin
White elevation of pustules
Tender
Nail pitting
Features of erythrodermic psoriasis (3)
Fine red scales that fall off
Itchy and painful
Nail pitting
Features of psoriatic arthritis
Joint inflammation
Nail pitting
Most common site of plaque psoriasis
Scalp and tensor regions
Most common site of guttate psoriasis
Trunk and limbs
