Erythromelalgia is a rare paroxysmal vasodilatory disease of unknown etiology. It is characterized by paroxysmal elevation of skin temperature, flushing, swelling, and severe burning pain in the skin of the extremities, with the toes and soles of the feet, and can be triggered or exacerbated by elevated ambient temperatures, and relieved by lower temperatures. 1, most common in young people, summer onset, winter relief. The performance of bilateral limbs symmetrical skin paroxysmal skin temperature increase, skin flushing, swelling and severe pain. The pain is paroxysmal burning pain, which is obvious and frequent at night and may last for minutes, hours or days. The pain is most common in both feet and can be seen only unilaterally in a few patients. Warmth, activity, dropping the extremity, or prolonged standing can cause or exacerbate pain episodes. Pain can be reduced and relieved by cold water immersion of the foot, rest or elevation of the affected limb. As a result, patients prefer cooler temperatures and are reluctant to wear socks or gloves. The disease progresses slowly. 2.Severe patients may develop ulcers or gangrene due to nutritional disorders. There may be sensory hypersensitivity in the lesion area, and generally there is no sensory disorder or motor disorder. 3, physical examination can see the affected skin vasodilatation, redness, pressure of the red can be temporarily disappeared, increased temperature, mild swelling and sweating, dorsalis pedis artery and posterior tibial artery pulsation slightly enhanced. Repeated episodes of thickening of the skin and nails can be seen.