Anaphylactic purpura is a vascular metamorphic reaction disease with a certain genetic predisposition, and patients may have skin purpura, joint swelling and other symptoms. After standardized treatment, patients have a better prognosis. 1. Allergic purpura is due to the body’s allergic reaction to certain sensitizing substances, resulting in capillary fragility, as well as an increase in permeability, blood extravasation, resulting in purpura, bleeding of mucous membranes and certain organs. The etiology of purpura is not yet clear, and may be caused by infection, heredity, environment, immune disorders and other factors. 2. Patients may develop skin purpura, which is manifested as purplish-red papules that do not fade when pressed. When some patients involve the joints, they may have joint swelling and limited movement. 3. Patients may take oral non-steroidal antidotes, such as acetaminophen and ibuprofen, or oral glucocorticoid drugs, such as prednisone and dexamethasone, under the guidance of a doctor. Some patients may also take oral antihistamines, such as loratadine and cetirizine. Most patients can improve their prognosis and quality of life with treatment. Once the diagnosis of purpura is confirmed, it is necessary to cooperate with the doctor to take treatment measures.