Psoriasis

Question 1

What is psoriasis?

Answer 1

Chronic inflammatory skin disease characterised by well demarcated inflamed scaly plaques.

Question 2

What is the epidemiology of psoriasis?

Answer 2

Equally common in men and women with bimodal onset: two peaks between 10-20 yrs old and 50-60 yrs old.

Question 3

What are the pathophysiological factors of psoriasis?

Answer 3

Multifactorial due to genetic and environmental predispositions.

Question 4

What are the genetic factors associated with psoriasis?

Answer 4

Patient commonly has a family history of psoriasis.

Question 5

What infectious factors can cause psoriasis?

Answer 5

Mostly caused by streptococcal infections; can also be caused by HIV.

Question 6

What social factors contribute to psoriasis?

Answer 6

Stress, alcohol, and smoking.

Question 7

What drug factors can trigger psoriasis?

Answer 7

Changing/new medication, drug classes such as beta-blockers, lithium, antimalarials, and tapering steroids.

Question 8

What immune system factors are involved in psoriasis?

Answer 8

Inflammatory cytokines and T-lymphocytes.

Question 9

What is Koebner’s phenomenon?

Answer 9

A phenomenon where psoriasis lesions appear at the site of trauma.

Question 10

What are the different types of psoriasis?

Answer 10

Chronic plaque psoriasis, scalp psoriasis, nail psoriasis, guttate psoriasis, flexural/inverse psoriasis, palmoplantar pustulosis, and generalised pustular psoriasis.

Question 11

Describe chronic plaque psoriasis.

Answer 11

Well-demarcated, pink/erythematous plaques with scaling, typically distributed over extensor surfaces and trunk.

Question 12

What are the characteristics of scalp psoriasis?

Answer 12

Well-demarcated scaly plaques extending beyond the hairline and onto the neck, associated with transient hair loss.

Question 13

What are the differentials for scalp psoriasis?

Answer 13

Tinea capitis, contact dermatitis, seborrheic dermatitis.

Question 14

What changes does nail psoriasis cause?

Answer 14

Chronic changes such as pitting, onycholysis, and subungual hyperkeratosis.

Question 15

What are the differentials for nail psoriasis?

Answer 15

Fungal nail infections such as onychomycosis, eczema, lichen planus.

Question 16

Describe guttate psoriasis.

Answer 16

Widespread, small erythematous raindrop-shaped plaques, most common in children or following streptococcal infection.

Question 17

What is the typical course of guttate psoriasis?

Answer 17

Usually acute and resolves spontaneously after phototherapy, but can progress to chronic plaque psoriasis.

Question 18

What characterizes flexural/inverse psoriasis?

Answer 18

Shiny, smooth plaques with few scales, localized to skin folds and intertriginous areas.

Question 19

What are the differentials for flexural/inverse psoriasis?

Answer 19

Seborrheic dermatitis, cutaneous candidiasis, tinea incognito, contact dermatitis.

Question 20

What is palmoplantar pustulosis?

Answer 20

Sterile yellow/brown/erythematous pustules widespread over palms and soles, associated with skin peeling and crusting.

Question 21

What is generalised pustular psoriasis?

Answer 21

Life-threatening form characterised by widespread sheets of sterile pustules on erythematous skin.

Question 22

What are the associated symptoms of generalised pustular psoriasis?

Answer 22

Associated with pyrexia and haemodynamic instability.

Question 23

What complications can arise from generalised pustular psoriasis?

Answer 23

Secondary bacterial infection, electrolyte disturbance, renal and liver impairment.