A 17-year-old white woman presented with a 2-year history of increasingly frequent episodes of erythromelalgia involving her hands, feet, and lower legs (Figure). She described the discomfort as “throbbing, burning, stinging.” Her symptoms occurred daily. The episodes involved her feet about 10 to 15 times during the day and involved her hands slightly less frequently. Whenever her feet got warm at night, erythromelalgia developed. These episodes were extremely painful. Generally, the erythema and pain occurred independently in the hands and feet. The symptoms were precipitated in her hands and feet by exercise; for example, walking precipitated the symptoms in her feet and legs, and writing precipitated them in her hands. Occasionally, the symptoms occurred when she was at rest, and they occasionally were worse at night. The symptoms lasted from minutes to up to 2 hours. She relieved the symptoms by cooling the affected area with ice and by raising the symptomatic limbs above the level of her heart. At night, she would stick her feet out of bed to relieve the symptoms and, during warm weather, used a fan.