There is no specific time for the high blood creatinine of purpura nephritis to come down, and it should be combined with the patient’s recovery. In mild cases, the blood creatinine value can be controlled within a few days, and the value of blood creatinine will decrease slowly; if the condition is serious, the duration of the disease will be longer, and it may not be able to be reduced for the rest of the life. If purpura nephritis causes high blood creatinine, it is considered that the disease has seriously involved the kidneys, resulting in impaired renal function. Treatment needs to remove the causative factors as soon as possible and keep away from allergens. If the value of creatinine rises gradually, it can be considered to improve renal perfusion and use prednisone acetate, cyclophosphamide, cyclosporine A and other systemic immunotherapy, and the creatinine may drop to normal in a few days. If the patient’s disease is serious and discovered late, and the impaired renal function has developed into a chronic stage, the blood creatinine may never come down despite active and effective treatment. The above medication should be used in accordance with the doctor’s instructions, and should not be used without authorization, so as not to aggravate the condition. Purpura nephritis patients, it is recommended to consult a regular hospital in a timely manner, under the guidance of a physician standardized treatment.