What is the test being done & what sign is it used to demonstrate?

Auspitz sign is characterized by:- a) Micaceous silvery white scales b) Burkley membrane c) Pin point bleeding This is seen in psoriasis & demonstrated by grattage test. Auspitz sign is presence of pinpoint bleeding at the base of a plaque after scale is forcibly removed in patients with psoriasis. The successive removal of psoriatic scales usually reveals an underlying smooth, glossy, red membrane (membrane of Burkley) with small bleeding points where the thin suprapapillary epithelium is turn off. The red membrane is known as Burkley's membrane.