Cutaneous Signs of Vascular Disorders: Polycythemia Vera
Four months after a patchy, macular, erythematous spot erupted on the dorsum of a 63-year-old woman’s left foot, the area became ulcerated, tender, and painful. The 1.2-cm ulcer was covered by a hemorrhagic crust surrounded by a cyanotic reticular discoloration of the skin. The patient’s white blood cell count was 15,500/μL; red blood cells, 7.7 million/μL; hemoglobin, 18.5 g/dL; hematocrit, 59.9%; and platelet count, 845,000/μL. Her distal pedal pulses were strong. A biopsy of tissue from the affected area revealed superficial thrombophlebitis. Polycythemia vera, characterized by an abnormal proliferation of bone marrow elements—erythrocytes, leukocytes, and platelets—was diagnosed. This disorder is also marked by increased red cell mass and total blood volume. The cause is unknown. Some patients with polycythemia vera are asymptomatic; others may exhibit a range of symptoms, including a ruddy complexion, pruritus, weakness, headache or light-headedness, visual disturbances, and dyspnea. Petechiae, ecchymoses, arterial thrombosis, thrombophlebitis, leg ulcers, and livedo reticularis are also seen. After the patient underwent phlebotomy for several months, her leg ulcer healed. Alkylating agents and interferon also may be used to treat polycythemia vera. Treatment of this disorder can reduce the incidence of superficial thrombophlebitis.