Lidocaine and mexiletine therapy for erythromelalgia.

A 25-YEAR-OLDwhitemanpresentedwithalifelong history of severe, sometimes excruciatingpain inhis legs,whichwereconstantly red and hot. He insisted on having his legs and feet constantly in ice water to relieve his severe discomfort. He required treatment with oxycodone and acetaminophen (Percocet) every 4 hours for pain. His mother recalled that from the age of 2 years his feet and legs intermittently turned a bright red, were hot to the touch, and were extremely tender. The redness and associated pain in his legs and feet became persistent. He learned to soak his feet in ice water for comfort as needed during classes in high school. He completely avoided wearing socks and only wore shoes when necessary. He attempted to play sports but had to stop intermittently to cool his feet with ice water because of severe burning pain and redness of both feet. When he was in high school, he took a job as a lifeguard during the summer, soaking his feet in the water. His social life was curtailed. He had a fan blowing on his feet all night, and he would get up for 1 to 2 hours during the night to soak his feet in ice water. He developed similar but milder pain in the hands. Therehadneverbeenaperiod inhis lifewhenthepain had resolved despite treatment with multiple medications, includingtricyclicantidepressants,systemiccorticosteroids, andnonsteroidal anti-inflammatorydrugs; transcutaneous electrical nerve stimulation; and multiple pain medication regimens that were coordinated by pain clinics. He started drinkingheavilyatage13years.Heusedcocaine,diazepam, marijuana, oxycodone and acetaminophen, and alcohol to try to get rid of the pain. He thought that cocaine worked best for the pain. He underwent detoxification as an outpatient in 1994. There was no family history of similar problems, and he was otherwise in good general health. During the 6 months before presentation, his pain worsened. He soaked his feet in cold or ice water to the point that he had them constantly submerged. He developed multiple small painful ulcers over his feet, ankles, and legs. A trial of sympathetic nerve blockade and epidural corticosteroids (exact procedure by history unclear) 3 months previously had given temporary (3-5 days) relief. Afterward, however, the pain worsened. Examination revealed a patient in discomfort, with his feet in a large bucket of ice water, which he carried with him. Grimacing and considerable expressions of pain were noted, and he had difficulty talking because of pain. Multiple superficial fibromembranous to purulentappearing ulcers punched out over the lateral aspect of the feet, ankles, and the lower part of both legs. Markedly erythematous and hot legs and feet (Figure 1) were noted. Physical examination and history were consistent with the diagnosis of erythromelalgia. Investigation revealed a small-fiber neuropathy affecting the upper and lower extremities. The affected areas were hot, with an increased laser Doppler flow, and a relatively low transcutaneous oxygen level was noted. The patient was hospitalized and a morphine patientcontrolled analgesia pump was started for pain. Topical treatments included continuous antiseptic wet dress-