Pitting bleeding is the most important sign of psoriasis, and the diagnosis of psoriasis can be confirmed on the basis of pitting bleeding, film phenomenon and silvery white scales. The droplet hemorrhage refers to the appearance of a translucent light red shiny film on the skin after scraping off the white scales, called the film phenomenon. Continuing to scrape off the film will cause the capillaries at the top of the dermal papillary layer to be scraped, resulting in many small bleeding spots, called the droplet hemorrhage phenomenon. The droplet bleeding phenomenon is an important feature in the diagnosis of psoriasis, which is a chronic and easily recurring disease, manifested as silvery-white scales, which are easily scraped off, and after scraping off the scales, there will be red spots, sometimes accompanied by obvious itching, which is difficult to be suppressed by oral medication when itching is intense.