Psoriasis vulgaris

Psoriasis vulgaris (or chronic plaque psoriasis) is the most common pattern of psoriasis seen in about 90% of the cases (1).

The plaques:

• are well circumscribed, round-oval or nummular (coin-sized)
• initially may present as erythematous macules (flat and <1 cm) or papules
• may have a white blanching ring (Woronoff's ring) in the surrounding skin (2)
• may be single or multiple covering the whole body
• vary in size - from a few mm's to several cm's (3)
• are red with scaly surface; reflects light when gently scratched, creating a "silvery" effect; more vigorous rubbing induces pin point haemorrhage (Auspitz sign) (2)
• occur all over body but with predilection for extensor surfaces - especially knees, elbows; lumbosacral regions; scalp; trunk, buttocks and nails (3)
• occassionally, involve penis, vulva and flexures, but scaling is absent
• scalp involvement is non-scarring - but there may be some hair loss
• lesions often symmetrical (3); chronic and stable

Click here for images of psoriasis vulgaris

Reference:

• 1. National Psoriasis Foundation. Plaque psoriasis
• 2. Langley R.G.B et al. Psoriasis: epidemiology, clinical features, and quality of life. Annals of the Rheumatic Diseases 2005;64(2)
• 3. American Academy of Dermatology 2008. Guidelines of care for the management of psoriasis and psoriatic arthritis - Section 1. Overview of psoriasis and guidelines of care for the treatment of psoriasis with biologics