Psoriasis

Question 1

What is psoriasis?

Answer 1

• Polygenic disorder and the phenotype is elicited by various triggers including trauma, illness and medications
• chronic dz w/ intermittent remissions

Question 2

age distribution of psoriasis

Answer 2

• bimodal
• 20-30
• 50-60
• mostly appears in 4th decade in women

Question 3

genetic association w/ psoriasis

Answer 3

i. Associated with HLA-Cw6 and HLA-DR7
ii. Pustular associated with HLA-B27
iii. Guttate associated with HLA-B13 and HLA-B17
iv. Erythrodermic associated with HLA-B13 and B17

Question 4

what disease has been linked w/ psoriasis?

Answer 4

• Crohn’s

- locus on chrom. 16

Question 5

triggers of psoriasis

Answer 5

• sunburn, drug eruption, virus
• strep infection
• HIV
• pregnancy –> pustular form
• hypocalcemia
• psychogenic stress
• drugs
• ETOH
• smoking

Question 6

what drugs can be triggers for psoriasis?

Answer 6

• lithium
• beta blockers
• antimalarials
• interferon
• rapid taper of steroids

Question 7

pathogenesis of psoriasis

Answer 7

• t cell are driving factor

- activated t cell secrete cytokines which activate neutrophils in the epidermis

Question 8

Auspitz sign

Answer 8

the pinpoint bleeding that occurs when plaque and underlying surface membrane is removed and is the clinical reflection of elongated vessels in the dermal papillae, in addition to thinning of the suprapapillary epidermis

Question 9

What is the MC form of psoriasis?

Answer 9

chronic plaque dz

Question 10

chronic plaque dz

Answer 10

• fairly symmetric distribution of sharply defined erythematous scaly plaques
• extensor surfaces***: elbows, knees, scalp, presacrum, hands and feet

Question 11

how to rank severity of chronic plaque dz

Answer 11

-PASI: psoriasis area and severity index

Question 12

What is the MC form of psoriasis in children?

Answer 12

Guttate psoriasis

Question 13

Guttate psoriasis

Answer 13

• more likely a hx of a preceding severe URI, esp. Strep inf**
• good prognosis w/ spontaneous remission after tx of underlying infection
• can sometimes progress to chronic plaque

Question 14

palmoplantar pustular psoriasis

Answer 14

• sterile pustules admixed w/ yellow-brown macules
• chronic
• commonly associated w/ inflammatory bone lesions

Question 15

inverse psoriasis

Answer 15

• in the axillae, inguinal creases, intergluteal cleft, inframammary and retroauricular folds
• can be triggered by local fungal infections
• characterized by shiny, pink to red, sharply demarcated plaques w/ minimal scale

Question 16

nail psoriasis

Answer 16

• fingernails more common than toenails
• effects the nail matrix and nailbed
• seen as pits, leukonychia or oil spots

Question 17

psoriatic arthritis

Answer 17

• occurs mostly after experiencing skin lesions

- negative serologies but erosive change on XR

Question 18

what are the MC sites of psoriatic arthitis?

Answer 18

• DIPs and PIPs
• “sausage digits”
• can also have a shortening of digits = “pencil in cup”