The child has purpura considered may be caused by infection, allergy, before treatment need to check the blood routine, urine sediment, to see whether there is corresponding inflammation and infection, whether there are other system involvement, also need to exclude the purpura caused by blood system disease. According to the situation, drug treatment and life adjustment can be carried out, as follows: 1. Oral antibiotics, such as cephalosporins or erythromycin, are needed when accompanied by inflammation and infection; 2. If there is no infection, anti-allergy treatment can be carried out, oral vitamin C pills, rutin tablets, compound glycyrrhizin tablets, and also topical glycopyrrolate lotion can be used; 3. Life and living need to be adjusted accordingly, avoid contact with spicy and stimulating diet, avoid The child should be instructed to take good rest and not to do strenuous exercise. And the child should not bend the knee for too long, and should put the affected limb flat in bed.