Psoriasis

Question 1

What is psoriasis

Answer 1

Chronic autoimmune condition that causes recurrent symptoms of psoriatic skin lesions
Variation in severity

Question 2

Psoriasis presentation

Answer 2

<35yrs
Patches of well-defined, dry, flaky, scaly, erythematous plaques. Appear raised and rough. Commonly over extensor surfaces of elbows and knees and on scalp.
May be itchy and may feel generally unwell

Question 3

Psoriasis pathophysiology

Answer 3

Rapid generation of new skin cells causing an abnormal buildup of keratin and thickening of the skin

Question 4

Psoriasis differentials

Answer 4

Fungal skin infection
Cellulitis
Eczema

Question 5

Types of psoriasis

Answer 5

Plaque psoriasis (most common) - typical thickened, erythematous plaques with silver scales, commonly on extensor surfaces. 1-10cm in diameter.

Guttate (teardrop) psoriasis (second most common) - many small raised papules across trunk and limbs, mildly erythematous and slightly scaly. Can develop into plaques. Often triggered by a streptococcal throat infection, stress or meds.

Pustular psoriasis (rare) - pustules form under areas of erythematous skin. Not infectious. Can be systemically unwell. Need hospital admission - medical emergency

Erythrodermic psoriasis (rare) - extensive erythematous inflamed areas covering most of the surface area of skin. Skin comes away in large patches resulting in raw exposed areas. Medical emergency - require hospital admission

Question 6

What is Auspitz sign

Answer 6

Small points of bleeding when plaques are scraped off

Question 7

What is Koebner phenomenon

Answer 7

Development of psoriatic lesions to areas of skin affected by trauma

Question 8

What is residual pigmentation

Answer 8

Pigmentation after lesion resolves

Question 9

Psoriasis management

Answer 9

First line:
Emollients (moisturise)
Topical steroid and topical Vit D analogue (calcipotriol) - Dovobet, Enstilar for flares
Second line:
Phototherapy

Question 10

Psoriasis associations

Answer 10

Psoriatic arthritis - occurs in 10-20% of pts with psoriasis and usually develops within 10yrs of skin changes.
Nail psoriasis - nail changes associated with psoriasis including pitting, thickening, discolouration, ridging and onycholysis (separation of nail from nail bed)
Psychological impact - anxiety and depression
Increased CVD risk