Purple fingers may be caused by lupus erythematosus or other diseases such as Raynaud’s disease or small vessel vasculitis. 1. Lupus erythematosus: that is, systemic lupus erythematosus, lupus erythematosus caused by purple fingers is mainly due to the patient by the cold wind, cold water stimulation caused by the symptoms of cold wind, cold water stimulation after the blood vessels will spontaneously contract, in this case, the fingers may produce obvious purple, red. 2. Raynaud’s disease: refers to the cold or nervous stimulation, spasm of the fine arteries at the extremities, so that the finger skin suddenly appeared skin purple, red, with local cold, abnormal sensation and other transient clinical phenomena, recurrent episodes, primary for Raynaud’s disease. 3. Small vessel vasculitis: small vessel vasculitis leads to redness and purpleness of the hand because of inflammation of the patient’s blood vessels, or cold wind, pain stimulation and other causes of redness, purpleness and other manifestations. The causes of purple fingers are many, it is recommended that patients go to the hospital in a timely manner to clarify the cause of the disease, under the guidance of the doctor standardized treatment.