Allergic purpura is a hypersensitivity reactive capillary and small vasculitis, characterized by non-thrombocytopenic skin purpura, which can be accompanied by arthralgia, abdominal pain and renal lesions . The cause is complex: bacteria, viruses, food and drugs, even malignant tumors and autoimmune diseases may be the cause of the disease. 2.Prodromal symptoms: non-specific . 3, skin symptoms: palpable purpura . 4.Joint symptoms: swelling, pain . 5, gastrointestinal symptoms: abdominal pain, nausea, vomiting, even vomiting blood, blood in the stool . Abdominal pain characteristics: mainly around the umbilicus and the lower abdominal region, location is not fixed, mostly paroxysmal colic, repeated episodes, abdominal physical examination without obvious muscle tension and fixed pressure points, a little improper eating can cause abdominal pain, often accompanied by vomiting, blood in the stool 6, kidney damage: urinary occult blood and urine protein. Treatment: 1. actively search for the cause; 2. prevent and control upper respiratory tract infection; 3. remove infectious lesions; 4. avoid taking suspicious drugs; 5. strict dietary control (light diet, liquid or semi-liquid); 6. bed rest as much as possible. Systemic treatment: 1, reduce vascular permeability drugs (rutin, vitamin C, etc.); 2, platelet aggregation inhibitors (dipyridamole, piperazine ferulate, etc.); 3, non-steroidal inflammatory agents: treatment of arthralgia; 4, glucocorticoids (the efficacy of the joint type, abdominal type is certain, skin, kidney type is more controversial) 5, can not eliminate the rash; can not reduce the procedure of kidney damage; can not shorten the course of the disease and reduce recurrence 6, early application is beneficial to improve the above; 7, immunosuppressants (azathioprine / cyclophosphamide): treatment of glomerulonephritis; 8, plasma replacement therapy, immunoglobulin therapy; 9, anti-infective: respiratory tract infections available penicillin. Chinese medicine treatment 1, licorice: compound diammonium glycyrrhizate, compound glycyrrhizin, compound glycyrrhizin, etc.; 2, salvia: compound salvia injection; salvia chuanxiongzin injection, etc.; 3, thunderbolt: better for joint type, kidney type; 4, panax ginseng; Yunnan Baiyao, etc.