Erythromelalgia and myeloproliferative disorders.

Erythromelalgia (erythermalgia) is characterized by attacks of severe burning pain, erythema, and warmth of the extremities, primarily the feet and, to a lesser extent, the hands. The distress is provoked by environmental heat, exercise, and dependency; it is relieved by exposure to cold and elevation of the extremity. Primary and secondary forms of erythromelalgia exist. Secondary erythromelalgia has been linked to a wide variety of diseases, the most common of which are certain myeloproliferative disorders: polycythemia vera and essential thrombocythemia. We describe, for the first time, a patient in whom chronic myelogenous leukemia was associated with the development of erythromelalgia, review the 60 cases in the world literature of erythromelalgia in patients with myeloproliferative syndromes, and compare the primary and secondary forms of the disease. Importantly, symptoms of erythromelalgia preceded the onset of a myeloproliferative disease by a median of 2 1/2 years. Therefore, all patients with erythromelalgia should be monitored with periodic blood cell counts. An abnormal hemoglobin level, white blood cell or platelet count, or immature cells in the differential count are not seen in idiopathic erythromelalgia and should alert the physician to the possibility of a more serious underlying disease process. Treatment of the myeloproliferative syndrome will sometimes alleviate the symptoms of erythromelalgia. Alternatively, a single daily dose of aspirin results in dramatic improvement in most patients with either primary or secondary erythromelalgia.