Erythromelalgia is a disease of the vegetative nervous system, including primary erythromelalgia and secondary erythromelalgia. At the onset of the disease, the patient will have redness on the soles of the feet, fingers, palms of the hands and other parts of the body. The cause of primary erythema gangrenosum is not known at present, and it is mainly considered to be related to the dysfunction of autonomic nerve center and the skin’s allergic state to warmth and heat. The causes of secondary erythema gangrenosum include erythrocytosis and thrombocytosis. At the onset of the disease, the patient will show redness of the fingers, palms and other parts of the hand, increased pulsatility, increased temperature, redness and swelling, and the symptoms will be aggravated by elevated temperatures and activities. The symptoms can be alleviated by elevating the affected limbs after the onset of the disease. If there is secondary thrombocytosis, you can take a small dose of oral aspirin; the use of prostaglandins, such as misoprostol, a small dose can relax the anterior capillary sphincter, and improve the symptoms. After the onset of the disease should be regular hospitals, under the guidance of the doctor’s treatment to improve the condition, to avoid blindly use their own medication.