How many days should be injected to get well in allergic purpura can not be generalized, need to be judged according to the patient’s condition, some patients may not need to be injected, the condition of mild patients will be good after 3~5 days of injection, if the patient’s condition is serious, it may need to be injected for 60~90 days to be good. Most patients with allergic purpura have a better prognosis, and some of them do not need injections; if the patient has simple allergic purpura, he will be fine after 3~5 days of treatment through injections; if the patient has renal-type allergic purpura and arthritic-type allergic purpura, he may need 60~90 days of injection treatment to be fine. The doctor should be consulted to determine the patient’s condition. If the patient’s condition is serious, the recovery time may be prolonged. It is recommended that the patient should ensure enough rest, timely medical examination of allergens, clear allergens should not be contacted after allergens. In addition, patients should keep the skin clean and should not scratch the skin. It is recommended that patients with purpura should consult a doctor in time to avoid delaying their condition.