Psoriasis

Question 1

definition

Answer 1

chronic relapsing and remitting scaling skin disease any age

Question 2

Risk factors

Answer 2

genetic

• positive FH - 30%
• concordonaxe in monozygotic twins - 75%
• ( (psoras 1-9) loci on chromosome 6 - 50%

Environmental

• orecipitated by drugs
• eg lithium and B blockers infection, infection
• stress

Question 3

Clinical features

Answer 3

• extensor surfaces, umbillicus, elbows, ears
• ALL ten fingers
  
  • nail pitting
  • oncholysis (nail lifting off)
  • dystrophy (thickening)
• flexural involvement around early
• silvery scale hyperkeratosis
• well demaractated plaques (raised areas >1cm - extensior surfaces
• Salmon pink plaques
• development of painful hacks ad fissures with plaques
• symmetrical

Question 4

pathogenesis

Answer 4

• final common pathway is hyperproliferating of epidermal keratinocytes
• reduction in transit time from basal cell layer - stratum corneum
• activation of T lymhcytes
• result is
  
  • parakeratosis- hyperkeratosis with retained nuceli in SC
  • acanthosis - thickening of epidermis
  • epidermal neutrophils and dilated dermal capillaries

Question 5

Types of psoriasis

Answer 5

pustular - lots of pustules

guttae- raindrop - strepthroat, self-limiting

Plaque - salmon pink, most common, raised, inflamed, white scales

erythroderma - >90% of body covered HDU

Question 6

Treatment

Answer 6

In order of increasing effectivenes

• topical creams + oinments
  
  • moisturiser- reduce dryness
  • steroids - reduce autoimmne, itching
  • vitamin D analgoes, coal tar
  • dithranol- retinoid slow down keratinocyte proliferation
• phototherpat
• oral Tbx