Purple plaques become bigger after friction on the feet, different treatments should be taken according to different causes, common causes include local capillary rupture, allergic purpura, idiopathic thrombocytopenic purpura and so on. Treatment includes local treatment, drug treatment, surgical treatment and so on. 1. Local capillary rupture: pay attention to rest, avoid strenuous exercise of the feet; local hot compresses, massage, etc.; orally take medicines to activate blood circulation and eliminate blood stasis (to promote blood circulation and eliminate blood stasis in the body), such as Shujinzhuyuanshiqi tablets. 2. Anaphylactic purpura: bed rest, reduce physical activity, prevent complications, oral vitamin C, rutin to improve capillary permeability, glucocorticoid therapy if necessary. 3. Idiopathic thrombocytopenic purpura: oral immunity drugs, such as glucocorticoids. Surgical treatment for severe cases. If the purple patches become larger after rubbing the feet, there may be other reasons, it is recommended to go to the hospital in time, under the diagnosis of the doctor for treatment.