Pigmented purpura is a group of skin diseases characterized by purpura and hyperpigmentation, including three types, namely progressive pigmented purpura dermatosis, pigmented purpura mossy dermatitis, and capillary dilated cycloplegic purpura. The common feature of the above three diseases is purpura and pigmentation, which can be manifested as pinpoint to rice-sized purplish red bleeding spots, also known as purpura, densely packed into patches and accompanied by brown or brown pigmentation, the rash occurs in the lower extremities, especially the lower legs, often symmetrically distributed, the course of the disease is chronic, no conscious symptoms, the specific clinical manifestations are similar to the name of the disease, such as capillary dilated annular purpura also The rash can be manifested as annular rash, capillary dilation, and pigmented purpura skin disease with scaling.