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 (1)
• may be single or multiple covering the whole body
• vary in size - from a few mm's to several cm's
• are red with scaly surface; reflects light when gently scratched, creating a "silvery" effect; more vigorous rubbing induces pin point haemorrhage (Auspitz sign) (1)
• occur all over body but with predilection for extensor surfaces - especially knees, elbows; lumbosacral regions; scalp; trunk, buttocks and nails (3)
• occasionally, involve penis, vulva and flexures, but scaling is absent
• scalp involvement is non-scarring - but there may be some hair loss
• lesions often symmetrical (1); chronic and stable

Click here for images of psoriasis vulgaris

Reference:

1. Psoriasis: The assessment and management of psoriasis. NICE Clinical Guideline (October 2012 - last updated September 2017)