Forty-three-year-old man, complaining of burning pain in his both toes, was admitted to our hospital. Routine laboratory studies showed the following: hemoglobin 15.4 g/dl, red blood cells 6.27×106/μl with mean corpuscular volume 77.8 μm3, white blood cells 6,000/μl, platelets 66.8×104/μl, serum Fe 40 μg/dl and TIBC 360 μg/dl. Platelet aggregate ratio, which was measured by the method of Wu & Hoak, was decreased to 0.64 (normal range; 0.88±0.09), and spontaneous platelet aggregation was not observed in vitro. Platelet life span of the patient was shortened to 5 days (normal range; 8.5±0.5 days). The patient was diagnosed as having polycythemia vera with erythromelalgia. Erythromelalgia characterized by burning pain and cyanosis was relieved by the ingestion of Aspirin 600 mg per day. The effect of Aspirin, however, persisted for only 5 days. Neither thrombotic occlusion nor inflammatory process of the toe vessels was histologically observed in the biopsied specimen. These results suggest erythromelalgia of the patient is closely related to either the activation of platelets, especially via cyclooxygenase pathway, or the peripheral circulatory failure caused by increased blood viscosity and decreased deformability of microcytic erythrocytes.
