Pigmented purpura refers to pigmented purpuric dermatosis, which may be associated with capillary wall lesions, increased venous pressure, diabetes mellitus, infection, and other factors. 1. Pigmented purpura dermatosis belongs to a group of diseases caused by lymphocyte-mediated extravasation of red blood cells. The etiology of this disease is not clear, but clinical studies have shown that the underlying cause of pigmented purpura dermatosis may be related to capillary wall lesions, and common risk factors include increased venous pressure, pathogenic microbial infections, chemical substances, and clothing allergies. 2. In addition, the occurrence of pigmented purpura dermatosis is also associated with diabetes mellitus, lower extremity venous thrombosis and other diseases. Usually, there is no obvious discomfort in the early stage of the disease, and some patients will have pinpoint-sized purplish-red petechiae, annular plaques, moss-like papules and other symptoms. Usually after regular treatment (prednisone) can relieve the symptoms, control the skin lesions, to achieve clinical cure. When the presence of pigmented purpura dermatosis is detected, the patient can cooperate with the doctor for active treatment and strengthen the management of daily life.