Psoriasis Flashcards
- pathophysiology (2)
- general risks (2)
- two type of onset and associated FH
- hyperproliferation of keratinocytes. infiltration of inflammatory cells. (cycle)
- genetic predisposition. environmental triggers
- young onset - usually with obv FH. adult onset - may have no FH
-precipitating(risk) and perpetuating factors.
bio (4). psycho(1) social(2)
- trauma
- infection - tonsilitis caused by Bhaem streptococci may trigger guttate, staph aureus, hiv
- hormonal - may improve during pregnancy, hypocalcaemia secondary to hypoparathyroidism is a rare precipitator
-medication - antimalarials, beta blockers, INF-a, lithium. rebound psoriasis may occur after steroid withdrawal.
-affective component
- sunlight - improves most cases, worses 10% cases
- smoking and alchohol -worsen
-common patterns (6)
-plaque pattern, guttate pattern, scalp, flexures, nail, palms&soles
plaque psoriasis most common type
-morphology. b(1)c(1)d(1)e(1) distribution (4)
- lesions have well defined border
- colour is pink or red
- diameter ranges from a few mm to a few cm
- the surface of lesions has centrally adherant, silvery white polygonal scales.
- distribution is symmetrical. affecting commonly elbows, knees, lower back, scalp
guttate psoriasis also common
- usually seen in who(2). often triggered by(1)
- distribution (2).
- morphology. type of lesion(1). a(1). c(1) d(1) e(1)
- course (2) complication(1)
- children and adolescents. often triggered by streptococcal tonsilitis.
- multiple macules. trunk
- macules, round, red, small, soon become scaly
- rash often clears within a few months. plaque psoriasis may develop later
-scalp psoriasis -scalp involvement common. psoriasis can oveflow just beyond scalp margin. significant hair loss is rare.
-nails -nail involvement common. signs (3)
-flexures - distribution(3). type of lesion (1). morphology- b(1)c(2).e(1). common in(3)
-nail signs - thimble pitting, onycholysis (separating of nail from bed), subungal hyperkeratosis.
-flexures - anogenital, submammary, axilliary. plaques. well defined borders. red, glistening. may have fissuring in depth of fold. mroe common in female, elderly,hiv.
-palms and soles. morphology. b(1). c(1).lesions may become inflamed with pustules. can be disabling. fingers may develop (1)
poorly defined borders. barely erythematous. hard to recognize. fingers may develop painful fissures.
napkin psoriasis - distribution(1). course(1) complication (1)
acute generalized psoriasis. rare, serious condition. Asx(1). morphology(2)
erythrodermic psoriasis - rare. precipitators (4). distribution (1). morphology(2). skin symptoms (2). Asx(2)
napkin - area outside nappy. clears quickly. pt at increased risk of psoriasis late in life
acute generalized - Asx fever. erythematous and pustular.
erythrodermic psoriasis - irritant affect of tar or diathanol, drug eruption, potent topical or systemic withdrawal. most of skin affected. universally red, variable scaling. hot and uncomfortable skin. associated malaise and shivering .
general Mx of psoriasis (5)
- education - explain disease and reassurance - some cases self-remitting
- topical
- uv radiation
- systemic
- can be combined*
- -*treat comorbid depression or anxiety
-vitamin D analogues. eg (3). indication (2) pro(3) cons (1). contrain(1) course (1)
vit d analogues - eg calcipotriol, calcitrol, tacalcitol
>mild-mod psoriasis, affecting <40% skin
>pros of calcipotroil - odorless, colourless does not stain, cons
>cons - may cause irritation if over applied.
>contraindicated in children
>can be used for 1 yr
retinoids - eg(1). indication (1) cons (1) contrindicated in (3) course(1)
-retinoids - eg tazarotene
- chronic stable plaque psoriasis
- irriatation as SE as with vit d analogues
-women with childbaring possibility, pregnancy, children,
-can be used for 12 wks at a time
topical corticsteroids
-indications (4). cons (5)
- minor localized psoriasis. limited choice areas (areas, face, genitals, flexures) tar and dithranol rarely tolerated, pts who cannot use other topical treatments due to allergy or irritatoin, unresponsive psoriasis on scalp, palms, soles.
- cons - dermal atrophy, tolerance, early relapses, occationally the precipitation of unstable psoriasis, systemic absorption causing adrenal supression rare
diathranol
-cons (3) contraindicated areas (3)
diathranol
stains purple (skin, clothes, bathtubs), therefore difficult application (only to plaques, dressed,avoid eyes), irritation to surrounding skin
-too irritant for face, genitals, skin folds.
coal tar preparations nb not carcinogenic!
-cons.(2) pros (1)
unrefined coal tar preparations are more affective but smelly and stain clothes.
can be added to bath
