Tang, female, 8 years old, was diagnosed as allergic purpura in the dermatology department of Hunan children's Hospital on December 15, 2021 due to "repeated hip and lower limb bleeding points for 1 year and aggravation for 10 days"。After treatment with methylprednisolone tablets, cetirizine, dipyridamole tablets and mucopolysaccharide polysulfonate cream, there was no significant remission. She went to the First Affiliated Hospital of Hunan University of Chinese medicine for treatment on December 25, 2021. Four diagnostic information: There were scattered ecchymosis spots on the buttocks and both lower limbs of the child, which were symmetrically distributed, bright red in color, no fading under pressure, no pain in the ankle, no abdominal pain, no epistaxis, no gringival hemorrhage, no edema, no cough, shed tears, stuffy nose, sneezing and other discomfort, occasional vexation, general spirit, occasional smell in the mouth, dry mouth, easy to sweat when moving, normal appetite, perspire during sleep, dry stool, normal urination, red and crimson tongue, and powerful pulse strings.,TCM diagnosis ,Purpura in children, The syndrome differentiation includes the syndrome of the bleeding due to blood-heat and qi failing to control blood.,Western medicine diagnosis, Allergic purpura.,Therapeutic methods ,According to the four diagnostic methods,Xijiao Dihuang ,Decoction was added to reduce heat clearing and cooling, promote blood circulation and disperse blood stasis, and then ,Guipi ,Decoction was added to strengthen the spleen and Qi, nourish blood and tonify the heart. During this period, it was combined with western medicine to fight inflammation and allergy.,Clinical outcomes ,The child recovered well, and there was no recurrence of purpura.