Summary of case history ,The child, Zhang Moumou, female, 3 years old,came to the pediatric outpatient department of our hospital for "recurrent rash of both lower limbs for more than 5 months". From March 2021 to August 2021, petechiae and ecchymosis occurred repeatedly in both lower limbs. After drug treatment,platelet fluctuation was 7×10,9,/L~63×10,9,/L. Four diagnostic information: a small number of needle like ecchymosis and ecchymosis on both lower limbs, restlessness at night, lack of fragrance in Nagu, difficult stool spacing, red tongue with little moss, and fine pulse count.,TCM diagnosis ,diagnosis of purpura, yin deficiency and fire hyperactivity syndrome.,Western medicine diagnosis ,immune thrombocytopenia.,Therapeutic methods ,Combined treatment of traditional Chinese medicine decoction and hormone.,Clinical outcomes ,The skin rash of the lower limbs of the children with curative effect prognosis retreated, and the platelet increased compared with the previous one.