The causes of red spots on the skin in leukemia are thrombocytopenia, inhibition by chemotherapeutic drugs, and also rare in allergic purpura. 1. Thrombocytopenia: the main manifestations of leukemia are infection, anemia and bleeding, and the main cause of bleeding is thrombocytopenia, which is mainly manifested as skin bleeding spots, petechiae, nosebleeds, gum bleeds and so on. 2. Inhibition of chemotherapy drugs: chemotherapy drugs such as cytarabine will be used in the treatment of leukemia, which will inhibit the hematopoietic function of bone marrow, which will further lead to the decrease of platelet level and coagulation dysfunction, and aggravate the symptoms of bleeding. 3. Anaphylactic purpura: leukemia will lead to a decline in body immunity, susceptible to infection, in contact with allergens, the occurrence of systemic small blood vessels of the allergic reaction of inflammation, mainly manifested in the skin hemorrhagic spots, arthritis, abdominal pain and so on. Leukemia skin red spots may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the physician to give targeted treatment or treatment.