Allergic purpura and platelet purpura are different in pathogenesis and clinical manifestations and treatment. 1. Allergic purpura: it is a kind of primary vasculitis that occurs in children, mainly involving small blood vessels, characterized by characteristic purpura, abdominal pain, arthritis and renal involvement; platelet count and function are normal; it is a self-limiting disease, and the treatment is mainly based on anti-allergy and symptomatic therapy; anti-allergy can be used in the form of calcium gluconate, and symptomatic therapy is mainly for pain relief and protection of the gastric mucosa, e.g., cimetidine. 2. Thrombocytopenic purpura: it is a group of hemorrhagic diseases caused by immune-mediated excessive destruction of platelets; it is a disease characterized by extensive skin, mucous membrane and visceral bleeding, thrombocytopenia, impaired maturation of bone marrow megakaryocytes, shortened survival time of platelets, and the appearance of autoantibodies specific to platelet membrane glycoproteins; the treatment requires hormone and immune-suppressing therapy, commonly used prednisone, dexamethasone, and so on. The two are different diseases, if the patient has the symptoms of purpura, it is recommended to actively consult the doctor to clarify the diagnosis, comply with the doctor’s instructions for treatment, do not blindly use their own medication.