Auspitz’s sign:
When the scales on a psoriatic plaque are gently scraped off, pinpoint bleeding occurs due to the dilation of blood vessels in the dermal papillae.
Koebner phenomenon (Isomorphic response):
development of psoriatic lesions at the site of skin trauma, such as cuts, scratches, or surgical wounds.
Candle sign:
• It is observed when the scales on a psoriatic plaque are scraped off, the skin beneath appears shiny and wax-like, similar to the melted appearance of a candle.
• This is due to the thickened skin and accumulation of skin cells.