Psoriasis

Question 1

psoriasis

Answer 1

• chronic inflmtn disorder of the skin
• peaks from 16-22 and 57-60 yrs old
• variable course of progression
• recurrent (will have for life; will get better but will have flare ups)
• lesions develop

Question 2

etiology

Answer 2

• idiopathic

- autoimmunity ->strong genetic component (~30%): HLA and MHC component

Question 3

patho

Answer 3

• lesions on surface of body (identified on outer, superficial layer of skin)
• no infection present
• cell cycle in epidermis -> rapid cell division and replacement of dead cells w/ new cells
• autoimmunity, inflmtn, accelerated cell cycle and epidermal thickening, remissions and exacerbations

Question 4

expand on the cell cycle in epidermis -> rapid cell division and replacement of dead cells w/ new cells

Answer 4

• basal layers = cells grow and are pushed up to surface as dead cells are continually sloughed off
• epidermal cell cycle normally takes 30d, but cycle is 3-4d
• division and differentiation = incomplete -> cells don’t slough off at top, but remain on surface and stack up to form scaly patches

Question 5

autoimmunity

Answer 5

• T cell autoimmune response -> abn T cell activity brings about self targeting
• trauma to the skin can trigger the response -> T cells activated -> release mediators that target keratinocytes and cells in bv -> triggers growth of keratinocytes instead of damaging cells = more keratin

Question 6

inflammation

Answer 6

influx of inflammatory cells (precipitated by skin trauma) -> inflmtry damage further traumatizes skin

Question 7

accelerated cell cycle and epidermal thickening

Answer 7

hyperkeratosis -> abn growth of keratinocytes and epidermal cell turnover results in scaly patches d/t cells stacking and no shedding

Question 8

remissions and exacerbations

Answer 8

can be triggered by stress, trauma, infection and drugs

Question 9

manifestations

Answer 9

• psoriatic patches (on scalp, knees, elbows, and sacrel region)
• nail dystrophy, erosion, and pitting (d/t abn amount of keratin)
• psoriatic arthritis in distal joints (complx)

Question 10

treatment

Answer 10

• no cure
• topical preparations
• systemic management

Question 11

topical preparations

Answer 11

• salicylic acid (softens lesion, facilitates removal)
• coal tar
• anthralin (modulates keratinocytes)
• steroids (decreases inflmtn, minimal SE)
• vit D (modulates keratinocytes and T cells)
• retinoids (anti-inflmtry, modulates T cells)

Question 12

systemic management

Answer 12

• methotrexate (immunomodulatory, antifolate, blocks cell division = decreases turnover of keratinocytes and T cells)
• cyclosporine (immunomodulatory)
• biologic agents (TNF: used for tx, not a marker. involed in apoptosis and regression of tumor)
• phototherapy (apply photons directly to areas of integument using UV-B rays to decrease rate of cell proliferation)