Purpuric dermatitis

Purpuric dermatitis is an allergic vasculitis of capillaries, also known as allergic purpura. It is an allergic vasculitis that mainly invades the skin and visceral capillaries and arterioles. Purpuric dermatitis is more common in the extension of the extremities, especially the extension of the lower legs, but it can also develop to the hips, forearms, and so on. At first, the dark red spots from the needles to the beans appeared in batches. A small number of adults may also develop blisters, necrosis, and ulcers. If treatment is not timely, it is easy to relapse. It is clinically subdivided into localized neurodermatitis and disseminated neurodermatitis.