患儿，女，4．5岁。因而色苍白、皮肤紫癜7天入院，伴乏力、纳差、萎靡，无发热、咳嗽、咯血、便血及血尿。否认肝炎等传染病史及服用氯霉素史，无放射线、苯等毒物接触史。体检重度贫血貌，全身皮肤散在淤点、淤斑，浅表淋巴结无肿大，心肺正常，肝脾肋下未触及。实验室检查； Children, female, 4.5 years old. Thus pale, skin purpura 7 days admission, with fatigue, anorexia, apathetic, fever, cough, hemoptysis, hematochezia and hematuria. Denied the history of hepatitis and other infectious diseases and taking chloramphenicol history, no radiation, benzene and other poisons exposure history. Physical examination of severe anemia appearance, systemic skin scattered in the deposition, ecchymosis, superficial lymph nodes without swelling, normal heart and lung, liver and spleen ribs did not touch. Laboratory examination;