过敏性紫癜(HSP)是儿童最常见的全身性毛细血管变态反应性疾病,常累及皮肤、关节、胃肠道及肾脏等多个系统,表现为皮肤紫癜、腹痛、胃肠道出血、血尿及关节肿痛等症状,累及神经系统(CNS)较少见。大脑后部可逆性脑病综合征(PRES)是由多种致病因素引起的以神经系统损害为主要表现的临床影像学综合征,其典型临床症状为意识状态改变、头痛、呕吐、视觉障碍,痫性发作及局部神经系统缺失症状等。头颅MRI是 Henoch-Schonlein Purpura (HSP) is the most common generalized capillary allergic disease in children and often involves multiple systems such as the skin, joints, gastrointestinal tract and kidneys. Purpura, abdominal pain, gastrointestinal bleeding, hematuria, Joint swelling and other symptoms, involving the nervous system (CNS) is rare. The reversible encephalopathy syndrome (PRES) posterior to the brain is a clinical imaging syndrome characterized by a variety of causative factors that cause neurological damage. Typical clinical symptoms include changes in consciousness, headache, vomiting, visual disturbances, Epileptic seizures and symptoms of local nervous system loss. Head MRI is