Psoriasis Flashcards
epidemiology
1-3% prevalence (2% UK)
M=F
any age; peaks 20s and 50s; 75%
histology
acanthosis excess keratin absent granulosum microabscesses (neurophils) large rete ridges, thin papillae dilated BV
causes/aetiology
genes: FHx 36%, MZ 73%, 1 parent = 25%, 2 = 60%
- polygenic; linked to HLA-Cw6/B17/B13
immunology
environment
aggravating factors
stress meds: BB, lithium, antimalarials steroid withdrawal obesity trauma (Koebner) alcohol, smoking sunlight in 5-10% (most improve)
types
acute guttate: post-strep; widespread randrops
chronic plaque: extensor plaques + scales
Flexural: smooth, defined patches
scalp: first/only site
palmoplantar: painful fissures, keratoderma
nail: pitting, onycholysis, yellow, ridging
erythrodermic: rare; skin failure risk
chronic plaque (90%)
D: symmetrical extensors
C: discrete plaques, Koebner’s, coalesce
M: silvery scaly (Auspitz), erythema/salmon pink, plaques, circ’d
nails changes: onycholysis, pitting, hyperkeratosis, splinter hge, crumbling, paronychia
flexural
D: folds/flexures
M: shiny, circ’d erythema, no scaling, may have central fissure
often infected (yeast/bacteria)
guttate
D: widespread, worse on posterior thigh and arms
C: Koebner’s phenomenon
M: erythema, small plaques and papules (raindrops), limited scaling
self-resolving (3/12) but may precede chronic plaque psoriasis
erythrodermic
>90% skin affected uncommon redness and scaling systemic upset: heat, protein, fluid loss admit!
pustular palmoplantar
D: usually symmetrical
M: sore, yellow/brown sterile pustules, macules, systemicall well
chronic and resistant;
F> M; associated with smoking
pustular generalised
rare; ‘von Zumbusch’; can be systemic and life-threatening
can occur with ordinary psoriasis
steroid withdrawal
rapidly spreading sterile pustules and background erythema
associated Sx
nail changes
arthritis: 10%,
impact (doesn’t always correlate with severity)
physical: pain, itch, bleed, arthritis, treatments (SE)
psych: appearance, self-confidence, stigma, ‘unclean’, shame, bullying
social: hobbies, occupatoin
management steps (4)
education: expectations, compliance, goals; chronic recurrent; PASI and QOL
topical: emollients, Vit D, keratolytics, tar, dithranol
phototherapy: PUVA/UVB
systemic: MTX, ciclo, acitretin, biologics (TNF)
topical Rx
coal tar: best for guttate;
-SE: smelly, sticky, staining, folliculitis, irritation
dithranol: inhibits Kcyte proliferation; good for individual thick plaques
- SE: stains, irritation, occlusion
vit D3: differentiation, inhibits proliferation, affinity; combo w/ steroids
-SE: hypercalcaemia, irritation (sensitive sites)
topical steroids: anti-inflammatory
-SE: rebound, tachyphylaxis (reduced effect if long-term)
topical retinoids
